I'm only about a year behind the times, but I've recently gotten into Borderlands. A couple of the guys I play D&D with and I get together just about weekly and do the co-op multiplayer.
Civilization IV (BtS with added leaderhead mods (I'm playing Hadrian))
DDO (D&D Online - happy 5th b-day guys)
Puzzle Pirates
Stainless Steel (Medieval Total War II Mod that kicks major tuckus)