For me the list would be:
5) Diablo 3
4) Torchlight 2
3) Assassins Creed 3
1) World of WarCraft: Mists of Pandaria
The reason I chose WoW as my top game for the year, is because not only is it my favorite type of game (MMORPG), but Blizzard managed to fix so many things that Cataclysm broke. They gave players CHOICES again (Yes, they feel mandatory to some, but at the end of the day, they just plain aren't), and made the story actually matter, because lets face it, it just didn't in Cataclysm. The constant engine upgrades are still keeping the game beautiful even by todays standards, something thats incredible for an 8 year old game.
If I had to choose a new game overall though, I'd probably say Dishonored or AC3