2011 was kind of a crazy year for me. I graduated college, moved back with my father after failing to find both an apartment and job, got a full time job not at all in the field I'm interested in, and started work on a lot of really cool projects. Perhaps out of a fear of success and failure (and quite a bit of procrastination) I also managed to play a lot of games this year. Of those however, most were not released this year, and very few were played to the end. I feel a bit odd about putting games on this list that I did not play to at least the end credits, but I suppose that's the way it will have to be.
First some honorable mentions.
The game I probably enjoyed the most was 2008's Defense Grid: The Awakening. It appeared in the Portal 2 promotional "Potato Pack" on Steam. Before Defense Grid I didn't really understand the appeal of tower defense games, but I found it incredibly enjoyable and sunk nearly twice as much time into then I did Portal 2. I found my picking up a lot of other tower defense games because of it.
Dark Souls is game that I wish I had played more. I didn't get very far in it and got tired of going over the same areas constantly. Still I really appreciate the game. It does something that few other games do. It doesn't look down on the player. Dark Souls is probably the most fair game I've ever encountered and that's what made the time I spent with it so much fun.
Might and Magic: Clash of Heroes is a game I wish I could put on this list, but since it originally came out in 2009 on the DS I didn't think it was fair even though I played the PC re-release. It's an incredibly fun game that I really need to go back and finish.