Hand Cannon Online has posted up an article of what they think are the Top Ten Two-Player games out there right now.
From the article:
Two-player games remain to be the brass ring in many relationships. Folks want a fun experience that fits into their busy schedule. A great many games which list ‘2-4’ players will feel as if a competitive element is missing with only two participants. Other games will even use a facsimile third player to shoehorn the game into working for just two