I tend to play just one game at a time, so currently it's Minecraft
Previous games which were my exclusive game include all the Civilization games (Alpha Centauri and Civ III were best), Elder Scrolls from Morrowind to Skyrim, Europa Universalis and Crusader Kings, Stardew Valley, Portal I+II.
World of Goo, Factorio and Sunless Sea get honourable mentions, and i'm rather looking forward to Sunless Skies when it drops in autumn.
I used to play first person shooters, but they're too twitchy for me these days. Also i gave myself RSI playing Quake II, and can't use a mouse anymore, so that sucks. Was fun anyway
Oh, and when i'm out and about i still play Pokemon Go