I have a personal soft spot for Doki Doki Literature Club because it got me into programming when i was young, but that's far more sentimental and to be honest i wouldn't play it again as an adult really. If i had to pick something functionally though I'd say Project Zomboid. there's a fuck ton of fun to be made in that, especially with Multiplayer. Even in singleplayer i like to turn on a NPC mod and assemble my own makeshift Walking Dead cast

Saw someone else out urquan masters, so I'll put Caves of Qud and Rain World. they both of some of the best pixel art ever, and caves of qud has some the most dynamic story telling in anything I've played

Gotta go with Dwarf Fortress. Been playing on and off for the past 10 years at least, it's just endless !!FUN!!

Some I really appreciate that I'm not seeing on this list:

I'm currently enjoying Blue Prince which is a fairly new rogue-like puzzle/mystery game it's hard to explain without spoiling but it's worth looking up.

Portals of Phereon is one of my absolute favorites. It's a fairly deep tactical RPG thing with loads of replayability. It's kind of like a Pokemon x FF Tactics but with monstergirls and it's also currently free while it's in development. Be aware it's extremely NSFW and horny, which I suspect is the main reason it's not as popular as some of the others listed (IE rimworld, stardew valley, etc.) however the horny is such a key point to it's original gameplay and world-building that it wouldn't be the same without it.

Thea: the awakening is a decent tactical RPG. I love it for it's original battle mini game, crafting system and world-building. It unfortunately has some balance issues and jankiness that prevents it from being an all time favorite, but it's definitely one I would encourage at least trying.

Thought of a few others:

• Reus (2nd one's alright, first one's excellent)
• Library of Runia
• Book of Hours
• Kenshi (saw it listed one other time, but it deserves a lot more love)

I really love Supraland, but it’s hard to convince people to try it for some reason.

Most of my picks have been mentioned already, but I had a blast with Mullet Madjack. A tongue in cheek riff on 80s anime in a boomer shooter where you have 10 seconds to live, but each enemy kill gives you 2 more seconds of life.

Banished, you can't get more Indie than just one guy's passion project.

I don't know what it is about that game but it really struck a chord with me and I've come back to it over and over. It's my favorite game to play when I'm sick and can't do anything. It's relaxing and peaceful and cozy while also being complex and ruthlessly challenging at the same time, so it's like spinning plates. Seems easy when you get the hang of it but it can all come crashing down if you make a bad enough mistake. It's spawned some copy cats, and I've tried them, but the original just gets me somehow.

I'll have to go with Selaco, it's not even finished (in fact it's approximately half done) but it feels more complete than any mainline Halo game after H:Reach. Looks better too.

Magicraft.

Clair Obscur: Expedition 33. If that doesn't count. Will....HoloCure or Noita or Parking Garage Rally Circuit.

Currently it’s Bellwright, among many other titles. what particularly tickles me about it is the shitty ai voices they used for the npcs. I am not pro ai by any means, but nothing makes me happier than hearing “all in a good days of work.” delivered constantly, in the most off-kilter reading imaginable.

The Cat Lady and the other games from Harvester Games 👀

Gunpoint. Charming, atmospheric, doesn't outstay its welcome.

Super Daryl Deluxe

That game has one of the best soundtracks I've ever heard in a game.

Undertale

hypnospace outlaw

Sticking only to ones I haven't seen mentioned:

• Tandis : geometry puzzler
• Gateways : a 2d portal-style puzzler
• Elliot Quest : pixel adventure
• Phoenotopia Awakening : also a pixel adventure, had trouble with the final boss but the rest is great
• Wuppo : flash-animation-style comedy adventure
• Alba : sweet game about a girl who loves wildlife
• Salt and Sanctuary : 2d soulslike
• Legend of Grimrock : tile-based first person dungeon crawler ("dungeon master" spiritual successor)
• A Short Hike (really short but amazing exploration game)

Ones I have seen mentioned but can't bear not to mention:

• TIS-100 : the finest of the Zachlikes; a programming puzzle game
• Crosscode : 2d adventure with incredibly fine-tuned combat and puzzles
• Outer Wilds : fantastic time-loop puzzle
• FTL : space adventure "one more run!" game
• Slay the Spire : deck-drafting "one more run!" game

Can't believe none of these haven't been mentioned yet: Starsector Kenshi Graveyard keeper Battle brothers Ghost of a tale

NaissancE

Can't really add much to all of the great games already mentioned. But I'll add one, because it was one of the best games I played in recent memory. Chants of Sennaar. Where to even start? Point-and-click adventure/puzzle game that is all about language puzzles. With great visuals and music. Really dig the eurocomics inspired style. I don't know why, but this game really touched me - maybe it's because the game is about uniting people in an age of discord.