Of the 2011 game titles, I only remember playing Portal 2, Super Street Fighter IV, Killzone 3 and Deus Ex: Human Revolution.
Among those that I played, I think Portal 2 should be in the top 10. I'm not a big fan of shooter games, they all feel very similar to me because of the gameplay. Portal 2 is something more refreshing and humorous.
Other games from 2011 that I'm looking forward to getting would be Uncharted 3: Drake's Deception abd Dark Souls.
So what are your favourite video games of 2011?