Hearts of Iron II: Doomsday - SO addictive!! Must not play as Soviets anymore, eyes burning! No must take England! :grrrrrrr:
Dawn of War + Expansions - Does get a bit boring every now and then.
World of Warcraft - For obvious reasons, but having other stuff to do means I don't get to play much.
Medieval: Total War - Mods! Mods I say!