If you're in the mood to play some Doom and want some Doom mods that pair well together but don't change the way Doom plays to an unrecognizable degree, I can highly recommend Gun Bonsai and Corruption Cards.
Gun Bonsai is a highly compatible mod that gives each of your guns an experience points bar, and dealing damage fills it up. When that gun levels up you get to pick one of four randomly selected modifiers for that weapon, such as 50% more shot speed, bouncing projectiles, debuffs on hit such as fire or poison, and a bunch of other effects. The gun is still operated the exact same way, otherwise. This means that Gun Bonsai works with other weapon mods! Every time you accumulate a total of 7 levels on your guns, you get to pick a modifier for the player too, like enemies dropping armor and health bonuses on death or faster weapon changing. It was just awarded a Cacoward, too.
Corruption Cards is a similar idea, except it applies to monsters. Every time you begin a map, you get to pick one of three randomly selected modifiers for the monsters for the duration of that map. There's 174 cards in the base mod, and it ranges from simple changes to weird changes like "every cacodemon is doubled" to "cacodemons can carry around other monsters" to "monsters can sometimes have tinier monsters as pets". There's a few environmental cards too, such as fireball traps spawning all over the map. Depending on your selected game mode, every three maps you choose a permanent modifier that carries with you throughout your game. Some permanent modifiers are unique, but some are the same modifiers you can usually pick, just permanent now.