Currently playing Skyrim, more than a year after everyone else.
It's pretty damn great. I play as a mage, something I usually don't in the Elder Scrolls series, and it's fun! And I can't believe the neverending amount of quests and places to visit, not to mention how awesome the region of Skyrim is in general.
As for game of the year 2012...sorry, I've barely played anything from last year, just The Secret World and Guild Wars 2, and neither kept me playing for long, even if they don't suck.