It's a close one to me.
Uncharted 2 was great; it taught me how to love again. At first I thought Nate was a douchebag and never played the first one, but after the hoopla here I decided to give it a try. Very engaging and gorgeous game. And then the multiplayer was also addicting.
But also I have a soft spot in my heart for NBA 2k11. With getting Michael Jordan on the front of the game (besides the money it took to get him on it), 2k was making a statement. That this would be the bestest basketball sim ever. And considering I've been playing basketball video games since Tecmo NBA Basketball and Hoops, it is. The Jordan Challenges were fun, and very nostalgic, to see Jordan go shot for shot with folks like Nique, Larry Legend, Magic & co. Then the modern teams were also good. It is not without its quirks, but I've probably played that just as much as anything else I own.
But UC2 wins, because I got to play with my ON brethren.
Watch me burn..