1. Mortal Kombat
This is the definition of "triumphant return." Every other fighting game developer needs to look at this game as an example of what you should do with a single player mode. Once they patched the online that was awesome as well. Spent more time with this game than any other this year. Sequel please.
2. Battlefield 3
The fact that I hate the single player and still placed this at #2 shows how strong the multiplayer is.
3. Saints Row: The Third
DO WHATEVER THE FUCK YOU WANT AND IT IS AWESOME. YOU SHOULD PLAY THIS GAME.
4. Gears of War 3
I admittedly could never get into the Gears multiplayer style (not for lack of trying, I played enough of the beta to unlock Cole Train), but going through campaign with your friends made up for it. Nice to see a mega popular series have the guts to give some pretty definitive closure.
5. Metal Gear Solid HD Collection
I actually never owned a PS2, and for some reason that copy of MGS2 I had for the original XBox never left the shrinkwrap (even to this day). This was a welcome opportunity to catch up on what was at one time (from the NES era through MGS1) my favorite game series.
Ballsy attempt to take the Rock Band "pro" idea even further. It wasn't perfect and this game is probably far too late to make an impact, but it was great to see an attempt at something new. People always say software will never replace real guitar lessons, and that is true, but this is the closest we've gotten so far.
7. Street Fighter III: 3rd Strike
Online Edition. This game is so bizarre to me. I play it, I'm frustrated by it, I complain and call it boring and not nearly the pick-up-and-play fun that SF2 or even SF4 are...but I STILL FUCKING KEEP COMING BACK TO IT. Very nicely done update to an older title.
8. Halo: Combat Evolved Anniversary
I was shocked how well this game holds up. The first few levels in particular are very well done. The Library still almost ruins it, but between the fairly simplistic gameplay and nice graphics update, this won me over all over again.
9. Sonic Generations
I almost can't believe I'm listing this myself, but this one convinced me that hope isn't completely lost. Just like...mostly lost.
10. Mortal Kombat Arcade Kollection
Ok, this game kind of stinks, I admit. It's loaded with technical issues, particularly in the sound department. There's an asinine glitch where when you unpause the game, you are unable to move for a moment. The terrible online play was only recently patched (although it is much improved now). Despite all of this, it's the first three MK games for 10 bucks, and sitting in a room with old friends playing these games for overnight marathon sessions was some of the most fun I had with a game this year.