As FPS (First person shooter) i must say Counter strike, i spend alot of my chilldhood playing that game. I mean thousands of hours (no kidding) and i was pretty good at it when i was aged 15-16 years.

As MOBA/ARTS i must say Dota, played that aswell when i were young but now i mostly play League of Legends in that genre. (Times changes)

However i'm not playing that much any more, most of my time i'm coding/programming and doing art works at my spare time (coing/programming at my daytime job aswell)