i have a lot.

the short list (always installed, i play em when i want to). if i reformatted my PC, these are what would immediately get reinstalled.
SFW: Senran Kagura games (burst, estival, shinovi) - hella fun sexy just button mash beatdown, Civ 4 (best Civ ever), Disgaea 5, Hearthstone, Path of Exile, Slay the Spire, One Finger Death Punch
NSFW: Out of Touch, Blondie Bear games (all), Ketzal SSP, Malignant, My Best Deal, On Distant Shores, Radiant, The Inn