Me and my friends used to go 4 player on Halo, Halo 2, Halo 3 (>_>) and CoD4 at their places. I was never good at console fpsing, but it's still kind of fun when you're playing with others. If one of our friends get a multiplayerable game, we play it alot. Little Big Planet for example is priceless when you play with your friends.
I'm never serious with games anyway, I just try to have as much fun as possible. There's a rivalry between 2 of my friends though, whenever we put a game in, they'd always get pissed at eachother: "fucking camper, fucking screenchecker, etc etc". So much fun.