For MMO's I almost exclusively play DPS (which means I'm useless, bla bla bla). I tend to play them as if they were a single player game though, and that's easier to do with DPS I think. I'm good at not pulling extra mobs or anything like that though. I'm going to try being a tank on The Old Republic soon just to see if I'd be any good at it.
Rpg: I overlevel and try to break the system. Even though I have fun with battles and everything, what I care about is the story and I like to speed through whenever I can/make the game easier so I can just enjoy the story. On second play throughs, I like to explore everything and try to acquire everything (unless it is Excalibur II).
FPS: I run around, shoot things, and die. Sometimes I'll get a kill. I suck at these.
MOBA: Just started trying out LoL. Haven't really established what kind of player I am.