So one thing I did recently was purchase one of those decommissioned HP Z440 workstations off eBay. It was I think a pretty good decision, though I had to upgrade the power supply in order to achieve my goals with it. Runs a Xeon 1650v3, which is more than enough for the things I've used it for, and I put in a GeForce 1650 GPU (PNY's dual-fan model, specifically) in it, which is actually pretty solid (note that it and the PC cost me about the same). Has a 256GB SSD for the OS and a 4TB HD for main storage.
And yes, the conventional wisdom is that the 1650 isn't as powerful as some of AMD's comparably-priced units, but with the power of Moonlight (https://moonlight-stream.org/) I can play my games remotely on my now decade-old gaming laptop, my phone, a tablet, etc. and there's nothing like that for AMD. Works quite well and means I can play some games when there's other stuff we got on the TV.
What surprises me about it is that it's better at emulation than I expected. Sure, I figured I could get stuff like Dolphin to run perfectly, but I didn't expect to be able to run Xenia on it. I dunno, this is maybe a me thing (I think you could argue the tasks that a Xeon CPU excels at make it better for emulation than a more consumer-focused CPU, something true for just about any server CPU, given that servers and virtualization are the peanut butter and jelly of remote computing), but I never really expected XBox 360 emulation to be something that would be feasible, especially on something I'd be able to afford.
Sure, it doesn't run Sonic Unleashed as well as a Series X despite the comparable price (it does consistently run better than on a 360, though, I'd say), but a Series X doesn't actually run any Wii or GameCube games. The Series line is surprisingly versatile for a console but I maintain this was the correct decision. That said, I'm stuck at native res (sorta-kinda 720p) for it, as trying to get it to render at a higher resolution brings it to a chop.
As far as a single machine designed to be compatible with as many games as possible go, it's hard to convince me this wasn't the right decision. I'm sure a newer i9 kind of thing would be much better at running, say, Dosbox-X, but there aren't many games that expect a Pentium II or better that I can't run natively. This is W10 Pro -- I'm sorry, I just don't want to go to the trouble of the extra configuration steps to get all the games I'd want to play working on Linux.
If you're looking for a budget high-compatibility gaming rig, I really can't recommend one of these machines enough. I actually had initially planned to get one of these to use as a virtual mac pro, and I won't rule out purchasing a second one specifically for that purpose, but gaming and virtualization aren't usually best-friends due to how anti-cheat software works, so I didn't want to try to run W10 under a hypervisor.
That said, I won't rule out getting a cheap second GPU that I can connect for virtualizing XP for additional compatibility, using PCI passthrough. Half-tempted to even try messing around with one of the NVS 285 cards I have, since there is a pure PCI slot on this thing and I've got one lying around that's not as compatible with my older computers as I'd hoped.
Other things I like: tool-less case, incredible cable management, box that doesn't look like the obnoxious gamer aesthetic. Big issues I have are the proprietary nature of the power supply both in shape and its connections to the motherboard.
If I get the chance I would like to put in a 1660v4 and a 3060 RTX in here, but neither is a particularly huge priority given how well it works with what I've thrown at it so far.
PS: Since I've been playing so much Sonic Unleashed, expect to see me post more about the game in the future. I have a few different posts about it I intend to write.