Maybe the best survival horror game yet.
2. XCOM: Enemy Unknown
XCOM is one of the many games this year that I couldn't play for more than an hour at a time because of the effect it had on my mood. This is a bleak, difficult game where it's hard to ever feel like you're winning so much as you're slowing your death spiral. This year has a seen a number of games that have attempted departure from the normal "power fantasy" theme, and XCOM successfully manipulates the player's morale in a way that might leave him brooding after a session. Not for people looking to unwind, XCOM is one of the windup-iest games I've ever played.
3. Hotline Miami
Hotline Miami is one of the most focused games I've ever played. The music, the dialogue, the cut scenes, everything is in service of selling you on the setting. This effectively disguises the twitchy puzzle-game underneath.
Journey is a triumph of production/presentation over mechanics. That Game Company seems to have religion about austerity of design, and they repeatedly prove that a great game can never be too simple.
Possibly as far as you could get from Journey, Spelunky is a cacophony of simple rules and systems, colliding and bouncing off one other to hilarious/deadly effect. Even in a year of no-nonsense no-hand-holding video games, Spelunky might be too punishing for it's own good. Still, the music is great, and the simple tile-based, randomly generated levels are quite good, and sell the isolation and peril effectively.
6. Binary Domain
This feels like a game from 2 or 3 years ago, but it feels like a very good game from 2 or 3 years ago. In a year where games have striven to mix in player-choice, or brutal difficulty, or subversion of expectations in story, a bog-standard third-person shooter with decent production values and voice-acting might not be avaunt-garde enough to garner real attention for GOTY lists. That's too bad, because this game is well executed, and contains some decent humor.
7. Mass Effect 3
Mass Effect 3 might not have even made it onto this list if I had played more games this year. Sure, the ending is fairly poor, but the important bits of a good Mass Effect game are all there. It's just not as special the second time around.
8. The Walking Dead
Brutal. I only made it part way through the second episode of this. Along with XCOM, this is another game that gave no quarter, and left me in a dark mood after playing. That said, the game is quite good. It's just not for me.