Ashley

In terms of 'official' releases, I have a really deep affection for Unidentified Fantastic Object, which is probably the hardest one in the franchise I've managed a 1cc on normal. It's just such a strategic-feeling game with how you manage ufo colours and spawn timing and the ways it enables strategic bomb routing through the game.

In terms of 'unofficial' games, I think it';s a tossup between

• Genso Wanderer, a really incredible mystery dungeon/roguelike game that is impossibly long, and detailed, with all kinds of metagame systems and some wildly hard boss fights.
• Azure Reflections, a sort of fan-remake of Embodiment of Scarlet Devil that turns it into a more-forgiving sidescroller with weird ideas like eating bullets to power up, and equippable gear. It's an absolute blast.
• Honorable mention to Labyrinth of Touhou 2 (or just "labyrinth of touhou" on english steam) which is a real love letter to etrian odyssey fans

Perfect Cherry Blossom. Bosses are varied and has a consistently banging soundtrack.

Shoutouts to the Prismriver Sisters' theme in particular.

i translated some interviews with the creator of touhou and it should explain some stuff about this series: https://en.touhougarakuta.com/index_interview/zun_long_interview-en/

Oh now this is a powerful question. In terms of official stuff, Scarlet Weather Rhapsody is my favorite. Its story mode just feels like a humongous step up from Immaterial and Missing Power's, with its actual narrative flow instead of every campaign just being an alternate ending. And I find the character of Tenshi Hinanawi compelling as hell, somebody who's so bored and lonely and lacking in understanding of the value of mortal beings that she threatened to do a little calamity to get friends. And then she didn't get friends, oops..... An oni did move in next to her, though, so that must've been nice (and lately Tenshi's character with Shion has just been.... amazing.....) Also its gameplay is a lot better than IaMP holy crap.

Future fighting games aren't for me, personally, but they seem neat in a lot of ways. And in terms of the shmups... I haven't played much of them at all, but, based on my present level of experience, I think Double Dealing Character's my favorite, just because, again, I really like the antagonists in it, pff... A couple of underdogs, one a complete bastard and one a lil lady who was lied to, y'know.

In terms of FAN GAMES....... There's a really well-made Pokemon game called Touhou Puppet Dance Performance that's basically Gen V mechanics in a Touhou-themed game, +no HMs and +a pretty cool "style" system where, instead of evolving, you choose between different styles that each have their own learnsets and stats and abilities, like Suika's Extra being Water/Fire type with a lot of weird and funny status shenanigans, but her Power style is Fire/Ground, if I recall, and also CHANGES HER SPRITE TO BE GIANT. IT'S GREAT. I LOVE THAT GAME. I DON'T KNOW HOW THE WRITING IS BECAUSE I PLAYED IT IN FULL JAPANESE SO IF THE WRITING'S BAD THEN PLEASE DON'T BLAME ME. (ALSO POWER STYLE SUIKA HAS TRUANT WHICH I LOVE BUT IT MAKES HER KINDA BAD)

I don't play many fan games though so my only other reccos are Mystia Lorelei's Izakaya (I personally have some qualms with its writing and its main "special customer" mechanic, but it is a... very relaxing and delightful-looking game. A very good restaurant sim if you just want comfy vibes with a Touhou aesthetic) and Touhou Library Survivors. I'm sure we all know about Touhou Library Survivors though. Love that game.

Lastly there's a Suika fangame that's been in development hell but may finally be getting some updates soon called Gensokyo Night Festival, and, while I haven't played it yet (I wanna play it when it's finished!!!) its aesthetic is undoubtedly amazing and its gameplay seems fun as hell as well. Also you play as Suika, and Ibuki Suika, the Free-spirited Old-timer, is a perfect character.

Anyway read Sobering of Lotus Eaters it's an official manga about a memory-deleting youkai becoming friends with Suika. There's no explicit yuri but it's yuri to me.

It's hard to come up with just one entry but I think for me it has to be Embodiment of Scarlet Devil. I played it at a moment when it really put a huge dent in my brain and made a big impact on my sound design and music composition style early on.

Shoutouts also to Imperishable Night and Subterranean Animism both for having really cool iterations on previous game systems and for giving tons of fuel to the yuri doujin artists in touhou circles. Puppet Dance Performance and Luna Nights as fan games are both incredible fun too.

Touhou 17.5 is a really really fun game once you get into it. It starts off pretty rough to play, with pretty awkward controls even for the more typical characters (and it lets you choose the 2nd hardest character to play as right from the get-go), but one of the things I like about that is how just a little bit of learning the game translates to a huge difference in outcome of playing it. It took me several hours and many game overs to beat just the route of the first character I played as, but even just playing through each character, I felt enough improvement that it got me into speedrunning the game, and now I'm at the point of trying to shave 8 frames off one boss to break the next second barrier. The initial hump is real rough, but once you get over that, the game is so much fun.
Shoutouts also to Labyrinth of Touhou 2, which is just one of my favorite turn-based RPGs ever. Etrian-esque and also rewards learning the game a lot by letting you do silly things like beating the main story with a single character 34 levels lower than is recommended a full party of twelve be.

14, Double Dealing Character! I got asked about this here. I also like 16.

Immaterial and Missing Power.

No, really, seriously. I loved that game dearly; it's what got me into fan translation work in the first place, as I was responsible for the translation modding on it (+ a few other Touhou games), as well as things like improving the netcode to add rollback support.

It's certainly not a popular choice, and I expect to be alone on this one here, but it still remains as one of my personal favorite, and most personally influential, games of all time.

Imperishable Night and Perfect Cherry Blossom got me into the series but Mountain of Faith is my favourite official game. Great Fairy Wars (12.8?!) also has a neat gimmick. I appreciate the fighting games but never really played them seriously.

I don’t know what my favourite fan game is but I’ve spent a lot of time in Mega Mari, Luna Nights and Blooming Chaos 2 (also Hotline Sanzu).

I only got into the Touhou games a couple of years ago, and that was thanks to the fangame Touhou Luna Nights, a metroidvania with "stopping time" as a central mechanic. I loved the design of that game because the time-stopping is as integral as the jump button, but it also made me curious to learn more about the world and the characters. This led to me trying Embodiment of Scarlet Devil and then the rest of the games.

I've only played a few of the mainline games, but I really, really love Imperishable Night. It has so much going for it! It has some of my favorite music (History of the Moon!!) and characters (Keine! Mokou!!). It has a huge cast of playable characters that adds a new dynamic to all of the story interactions. It has the incredibly memorable Stage 4, where you have to fight the one of the two starring heroes of the series in a hugely arduous and flashy battle. It has the time mechanic, which is just interesting enough to make you think about the game in a new way without getting too complex... I love it!

(I've also started playing another spin-off game, Touhou Mystia's Izakaya, which has so far been a really fun entry in the restaurant genre ~)

Scarlet Weather Rhapsody is the one that I got obsessed with for quite some time and still consider one of my favourite fighting games.

For official games I have an equal appreciation for 10-13, but 11 Subterranean Animism would probably be my number one pick. That was the game that came out at the peak of my interest in the games, and the difficulty made it a really satisfying grind to come back to over and over. The particular soundtrack and aesthetics of that game are some of my favorites in the series too. I unfortunately fell off the main series with 14 when I got too busy with university, and nowadays my hands and vision are too degraded for those long SHMUP grinding sessions I used to have LOL.

For fangames, I have to give a shoutout to Lost Branch Of Legend, a super fun Slay the Spire-like with an MTG color system, it kicks ass.

Touhou Mystia's Izakaya, Touhou Luna Nights and Shanghai.EXE: Genso Network.

Touhou Luna Nights, for sure. I am very bad at bullet hell games.

i'm a big fan of shoot the bullet! i really like the creativity involved in a shmup with no shooting, and i think it's really well balanced while being challenging, and has some really cool patterns

in terms of non-zun games i really like patchcon defend the library

Imperishable Night (8) and/or Subterranean Animism (11), but I'm begging anyone with even a passing interest in roguelikes/mystery dungeon or even just dungeon crawler RPGs generally to play Gensou Wanderer.

For the main games, Wily Beast and Weakest Creature and Unconnected Marketeers are my faves for being weird as hell. WBaWC has a very surreal tone and progression and has my favorite setup for a final stage. UM is a very fun experiment with roguelike trappings that allows for some neat builds.

17.5 is a really fun arcade boss rush game and has some incredible art and theming. Yuuma is maybe my favorite final boss in the entire series.

Fantasy Maiden Wars is my favorite fangame series, doing so well at being a Super Robot Wars that they might be my favorite SRW games on some days.
They found a way to tie spell cards into how SRW stages are presented, in both gameplay and narrative, allowing for climactic battles that actually change the tactical situation of the map, turning what would be a curb stomp in your favor in most SRWs into legitimately scary encounters.
It's rendition of Subterranean Animism and Utsuho is legit great.
I really hope the complete box collection gets a full and polished translation at some point

Imperishable Night and Fairy Wars are peak Touhou to me.

I just love the unique mechanics each had (2 characters & freezing), the OSTs are among the series' best and they have pretty unique presentations (the time-based elements in IN and being able to do the first 3 stages in whatever order in FW)

Also the "mash shift till the opponent or your wrist dies" tech is one of my best memories

I'm gonna stick to talking about shmups in this response, since plenty of people have other genres handled (though I second any Labyrinth of Touhou 2 recommendations).

Touhou Shinreibyou ~ Ten Desires is my favorite official Touhou game. On the surface it's a bit odd among the series, having generally easier bullet patterns but also not offering as many extra lives or bombs in return, but the way its unique spirit items work gives the game a fast-paced risk-reward where killing enemies quickly and rushing to the top of the screen to collect spirits will reward you with the ability to activate Trance more often, which makes you invincible, powerful, and makes spirits, bomb pieces, and life pieces worth much more. It's a game that can be pushed as far as you feel the need to, plus it has unique vibes even by the series' standards, with an unusually chill soundtrack.

Wonderful Waking World is a fangame that takes a very no-frills approach to gameplay, focusing on simple mechanics and higher speed than most Touhou games. This makes it very exciting and easy to pick up, despite its difficulty. The plot is also light and funny in the manner of some of the earlier official Touhou games, with a varied cast of original bosses that even features a few cameos from some oddball fan characters from around the internet. It also has a nice simplistic pixel art style that stands out among Touhou games.

Blue Devil in the Belvedere is another fangame, this one focused gameplay-wise on a "Power Overwhelming" mechanic that works very similarly to Hypers in Dodonpachi Daioujou. It's a simple system that feels good to use as you unleash powered-up shots all over the screen. The game also has gorgeous art and excellent music, and a plot with a surprising bit of nuance to it in regards to the situation of the various official characters and their home nation.

Phantasmagoria Trues is the last one I'll bring up here. It's a very old fangame, and you'll probably need Locale Emulator to run it (plus something like Antimicro if you wanna use a controller). Unlike the two mentioned above, it features no original characters, and in fact no story at all, and its music is all free stock music (though still very good). Instead, it's a veritable smorgasbord of well-realized shmup mechanics, high-intensity stages, and wicked boss fights featuring various classic Touhou characters. It's something you play solely for the gameplay, and it's unbelievably good at that.

I can't think of any fangames I particularly like so it's all about the Imperishable Night, though in terms of fighters it's Urban Legend in Limbo

in terms of fangames: Labyrinth of Touhou (2) is excellent and its recent Steam translation is a miracle. I find it to be fairly difficult though. Genius of Sappheiros may be tougher but I have a soft spot for it. Touhou Puppet Dance Performance (look for the Extended mod!) is great and worth checking out for any fans of Pokemon/Cassette Beasts out there. There's also a beat-em-up called Touhou: Wandering Souls which is very impressive for being made in RPG Maker, even though I don't actually remember how good it is.....

For official games, LoLK is probably my favourite overall; I love pointdevice mode, I love Clownpiece, I love the higher difficulty without being punishing.
SA is one I keep coming back to as well; it has some of my favourite songs, and the stage 6 boss is so incredibly dramatic, what with the sirens and warnings flashing on the screen, and the intense music.

For unofficial games, Mystia's Izakaya is just so good. It drew me in in a way few other story driven singleplayer games have, and the art is so cute. It's also about the only game of its type that I can pick up after months and not feel lost, or want to start over.
Lost Branch of Hourai is also really good. I find it a bit more engaging than Slay the Spire, though it is still far from done.

Utsuho's theme is stuck in my head forever so Subterranean Animism (11). It's mostly characters that stick in my head as likes. I like earlier windows games a little more than others but I like all the games and the fan games I have tried in roughly the same level of "like". So yeah, I like Gensou Skydrift about as much as any of the fighter spinoffs which I also like.

my favorite mainline game has to be mountain of faith. the soundtrack is strong from start to finish. plus, the cast is absolutely iconic-- many of the characters go on to play large roles in future games and manga, like sanae, aya, nitori, kanako, etc. gameplay-wise, i enjoy the strong emphasis on survival and the unobtrusive faith gimmick. it's a touhou game that feels extremely touhou.

as for fan games, i really love servants of harvest wish. it has an excellent soundtrack, entertaining characters, and a resource and scoring system that is easy to understand. great game for beginners and experienced players alike. also, it's free to play on steam *nudge nudge wink wink*

another fangame i absolutely adore is elegant impermanence of sakura. it has beautiful art, music, and patterns, although it's chaining system for score and resources may take a bit of learning.

Imperishable Night for having one of my favorite casts, music, and being the first game that felt accessible enough to make me feel like I could really get anywhere with it (which I think it something EoSD is not really well suited for for people totally new to the genre so I hate it when people say "start with eosd" to newcomers like it's some kind of strict rule.)

i haven't played a lot of fangames, so there's not many of those i can really comment on. in the past my go-to answers were IN and DDC, which i feel have pretty nice difficulty and variety with relatively parseable scoring and overall design, but these days i have to say i have a really soft spot for hidden star in four seasons as my favorite of zun's games. the extra stage in particular is my favorite in the series, with a slight twist on the main game's mechanics and motifs that really makes the stage a fun kind of puzzle to play with, and i love the music all the way through, and the shield activate in general is...well, really overpowered feeling, but in a way i feel that's representative of modern doujin shmups, haha...it's a solid example of the genre and an appealing presentation of all the things i think zun does best. although i think that's a pretty unpopular choice overall, and it doesn't seem like anyone else in this comment thread has mentioned it, haha

the fan games that really stick out in my mind are suwapyon 2, a weird 3d bullet hell where you have to jump over bullets on the ground as part of dodging, and the zun-affiliated tasogare frontier game whose title is commonly referred to in english as "satori komeiji's mental education" (i hate how clunky that sounds but i don't have a better suggestion), since i feel like i've never seen anything quite like them. the latter does have aspects that remind me a bit of lemmings or chip's challenge, but i really can't say i've seen a singular game that it really seems to be based on.

i've also played a ton of touhou spell bubble, the taito game that's got puzzle bobble as the basis with some music game elements layered on top, and i think that the fighting games are really cool, especially the first one (iamp) and the most recent couple.

My favorite official release by far is Impossible Spell Card. I adore the conceit of a game where you're encouraged to cheat to succeed at absurd tasks, and some of the series' more creative patterns can be found in that game.

For fangames, the one I've played the most by far is Touhou Lost Branch of Legend, which is explicitly a game patterned after Slay the Spire, but combining Touhou and Magic: the Gathering in that framework. It's really, really well-made, and I enjoy it a ton. Additional special mentions go to how Touhou Luna Nights is one of the slickest short experiences I can think of, the interesting gameplay of Mystia's Izakaya, and the best Super Robot Wars games: Gensou Shoujo Taisen.