The categories that I like, and that I am comfortable playing are: 2 d MMORPG, pixel art, mud, text, turn based.
For me sandbox, management building or simulation, strategy especially the 4x type, 2d or pixel art especially isometric one (I cannot stand with 3d most of the time because of my motion sickness except mount and blade thankfully), and at least I can be a god, dragon, king, or knight and in medieval period (Which not necessarily only exclusive to europe but the general period of the world at that times).
4X strategy and grand strategy games are cool (Civilization, Europa Universalis, Age of Wonders, etc.)
I find myself more partial to some fun little action adventures though (Tunic)
And of course, there are CRPG games which can be very fun and detailed, if quite long and hard to get through (Pathfinder: Wrath of the Righteous). I really want to finish my run of Pathfinder WotR in particular, since I get to be a fox character who punches monsters in the head, and that's just awesome.