1. Mass Effect 2
Game of the Year, and it came out in January. Better than the original in most ways, and only falling a little short due to being the middle chapter of a trilogy. Mass Effect 2 is one of the best games in history.
2. Red Dead Redemption
A complete surprise for me. Rockstar's finest work in my opinion, and without question one of the best games on consoles this generation.
3. StarCraft II: Wings of Liberty
Truly a masterpiece of storytelling in a singleplayer RTS. Blizzard has nailed down how to do real-time CGI-level player interaction, storytelling in an RTS, and an astonishing multiplayer matchmaking system all in a single release. The whole world will play this for its multiplayer, but the singleplayer is mind blowing.
4. Sid Meier's Civilization V
It's crazy to think that without changing the core formula or gameplay of a Civilization game it could still be one of the best games of the year, but it's totally true here. They streamlined everything about it, made it prettier, and basically made it run perfectly. It's the ultimate strategy game.
5. Heavy Rain
A truly unique game that, for me, lived up to the hype. Heavy Rain has a gripping story, and gameplay that has never been done before. Quantic Dream's craziest game yet, and it works.
6. Assassin's Creed: Brotherhood
What Ubisoft Montreal has accomplished in 3 years is astounding. Assassin's Creed 2 was an amazing game that improved on the first in every way. Brotherhood comes only a year later, and improves on everything yet again and still manages to add an awesome multiplayer mode.
7. Alan Wake
Rarely does a game this long in development end up meeting expectations, but Alan Wake did just that. Another game proving that games can have more compelling narrative than any other medium. This game will be remembered for doing about fifteen different things before anyone else had figured them out.
8. Battlefield: Bad Company 2
Without question the best multiplayer shooter on consoles. They changed the game and upgraded it just enough to make the sequel feel fresh. They refined everything they needed to, and expanded in a lot of areas. Early server problems and a more-serious campaign slightly mar what is otherwise a fantastic game.
9. Call of Duty: Black Ops
This might be my favourite Call of Duty. For a series that fell off the deep end for me with Modern Warfare 2, I did not expect Black Ops to bring it back full swing. The singleplayer is awesome, the multiplayer is unique enough, and zombies are zombies. Treyarch is at the top of its game.
10. Fallout: New Vegas
I -have not- finished this game, yet I feel it belongs on the list for me by default. The world of Fallout is so well realized and New Vegas adds just enough to the formula to keep it going. While I hope this is the last Gamebryo game we ever see, it's a fitting farewell.