I'm the guy who just has a laugh and dicks with people in the game.
If I want to annoy my own team I'll do something counter productive in an objective gametype, act like a dildo over voice chat so people yell at me, ect. or ill do stuff like go into team doubles with a friend (halo) and we'll both hide somewhere/repeatedly suicide so the other team gets really aggravated and then send them voice messages in which i sing dumb songs.
If I feel like actually playing the game I'll just do whatever is most fun to me and don't really give a shit about score or rank. I use the scout in TF2, my MW2 primary class involves marathon, lightweight, a throwing knife, and akimbo p90s, back in cod 4 I would try to sneak up on people and overcook a grenade behind them before they noticed, and as a general rule I always just sort of run in rambo style and try to take a few guys down before I die.