@Salyon , in terms of played at a competitive level, none comes to mind. There is a lot with 2v2 options but none balanced around it. I'd suggest an RTS such as say Sc2, because while it may not be balanced around 2v2, odds are you will never reach the level of game play where balance actually matters. (ie diamondish).
---------- Post added 2013-02-05 at 08:11 PM ----------
Bynaric. Try raiderz or Tera, both can be downloaded for free