I play Magicka, although at the moment I'm doing a playthrough of Dragon Age: Origins (with quite a few mods!) and waiting for a confirmation that Magicka has been more or less fully patched and is perfectly playable before I start really getting into the co-op.
My Steam name: Astalano
I'm from Cyprus (near Turkey and Greece) so it would be pointless to play with Americans as my ping would be too high. Just throwing that out there. ^^