In terms of games I've actually played from this year I'd have to say Diablo III, but I will need to think on it some more, and whether I feel like I can nominate any game I haven't played.
I'd consider dishonourable mentions for Halo MCC and Driveclub for having unacceptably broken online at launch. I'd also consider Destiny for "worst game everybody played". Dunno who should be considered for the nickel and diming award.
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix