Yeah... I'd have to call foul on that last one too. No way was Call of Doody: Bullplops the best game of 2010.
On a different forum, I voted Halo: Reach, simply because it's keeping the tradition of split-screen multiplayer alive, without following the masses into the "Online or bust" deathpit.
Looking back, I'm leaning back towards Mass Effect 2, as it has a lot more willpower-longevity* AND doesn't sell out to the multiplayer crowd. Something that requires a very special game to do.
*If you've never heard of willpower-longevity, it's because I just made it up. It's essentially how long the average player will be willing to sit down and play the game, not just how long it is.