I dont have a PS3
Here is a breakdown of my COOP/Multiplayer games:
360: Red Dead Redemption, GTA4+DLC, Crackdown, Borderlands+DLC, Red Faction Guerrilla, Viva Pinata TiP, Too Human (never played it yet), Marvel Ultimate Alliance2 and NHL10.
XBLA Games: BF1943, Bionic Comando Rearmed, Castle Crashers, N+, Splosionman, Peggle, Assault Heroes, Worms 1&2, Uno, and Im thinking about buying either Toy Soldiers and/or Risk today.
PC: Alien Swarm, Full Spectrum Warrior 1&2, L4D2, Multiwinia, Civ+DLC, Titan Quest, Team Fortress 2, SplinterCell Chaos Theory, Warhammer DOW 1&2 + DLC.
I heart coop gaming, so dont be shy. Im up for it all!