What games do you play multiplayer with?

Right now, all I play online is Halo, because Civ4's loading times are impossibly slow for me to play MP comfortably.

world of warcraft!

I play WoW, and I often play Halo 2.

Call of Duty: United Offensive (username: Jasper Hawk, but more likely to have the initials JH at the beginning).
Joint Operatinos: Typhoon Rising (will have Hawk in the name somewhere, I change it whenever I accidently TK a little too much)

Counter-Strike Source, Battlefield 2 and Call of Duty 2 are the ones I happily play on random servers.

Civilization IV I play with friends.

Enemy Territory and possibly Starsiege Tribes in the future.