Great list.
I completely forgot Final Fantasy 13....so I put that in the place of Darksiders in my top 10, and bumped darksiders into the honorable mentions list...bumping out Heavy Rain.
TOO MANY AMAZING GAMES MUST MAKE LIST LONGER!!!
15. Vanquish
14. Pac-Man Championship DX
13. 3D Dot Game Heroes
12. Final Fantasy XIII
11. Sonic Colors
10. Castlevania Lords of Shadow
9. Darksiders
8. Metal Gear Soild Peace Walker
7. God of War 3
6. Donkey Kong Country Returns
5. Bayonetta
4. Red Dead Redemption
3. Fallout New Vegas
2. Super Mario Galaxy 2
1. Mass Effect 2
Honorable Mentions: Goldeneye, Assassin's Creed Brotherhood, Red Steel 2, Alan Wake, Metroid Other M, Halo Reach, Lara Croft and the Guardian of Light, Dead Rising 2, Bioshock 2, Sin and Punishment 2.
Look at that!!!!! This is why this past gen was truly the greatest generation of games. Maybe not the most influencial or groundbreaking but the level of quality throughout so many games was crazy. Every game in my top 12 is a 9 or higher for me, most lists i struggle to find 5 of them. And that is that I have a bunch of games to play from this year like Just Cause 2, Yakuza 3, Civ 4. Mass Effect 2 is one of the greatest games ever made, Galaxy 2 is as well. Red Dead on many years could have easily won my GOTY. We got the best 3D Sonic ever. Action game mania with three excellent ones. It just had it all.
As always the 4th/5th year of a gen is when you hit the peak, after this it was a slow decline to what we got last year.
Anything below no 6 should be cut off your list 
Well jesus fucking christ its 2010, the Xbox 360 has been out for 5 years so surely its going to be replaced this year right? LOL NO.
That said, there was some really awesome games in 2010 and I'm gonna share them with you now. Please Understand.
HONORABLE MENTIONS: