CRPG
Dota2
Diablo II
Minecraft
Dungeon Crawl Stone Soup
Yume Nikki
Yume 2kki and other spinoffs of Yume Nikki
Space Funeral
The Elder Scrolls IV: Oblivion (I had a craving, don't ask)
Warcraft III (still fun to play horrible custom maps online from time to time - they are like dota's inbred siblings)
SimEarth
SimAnt
Wolf
Envirobear2000
A few more, but I hardly touch anything other than CRPG, Diablo II, Minecraft, and Dota 2. Stone soup is a nice turn based nethack style game that I can play at leisure if I'm half busy with something else. Default tileset is really nice and makes it feel more like a NES/SNES game than ASCII Matrix shit.
Yume Nikki is really cool and you should read about/watch a video of it if you don't have time to play it. The art style and dreary lonely dreamy setting is something I have craved without knowing my craving. It's like having a fever dream about playing an imaginary video game. That happened to me a few times when I was a kid.
edit: I play more games but they are physical copies of older console stuff, not emulated on my computer. Been lovin' me some hack 'n slash sidescrollers lately.