Before I get into it, a few honorable mentions:
Okamiden: A strong sequel to what I consider to be the greatest game ever made. I now know the series is in good hands over at Capcom's internal dev teams.
The Elder Scrolls V: Skyrim: I only just started this a few days ago, so I haven't had enough time to really sink my teeth into it (figuratively, of course). I'd like to see more before I claim it to be one of the year's best, so that's why I've left it out of my list. Damn good game, though. Incredibly detailed world. Easy to lose hours just on side content. In fact, it's 'cause of Skyrim that this list is going up so late. If it weren't for that, I'd have probably gotten this up a few days ago!
NightSky: A splendid little puzzler with a cool atmosphere. Maybe a bit too much abstract, though I had fun when I wasn't screaming in frustration at the absurd level of precision being asked of me.
Voxatron: I still don't know if I completely understand what a voxel is, but they certainly made a cool game. A dual-stick shooter made around user-created levels, Voxatron's got some amazing potential behind it. The game just launched in Alpha a couple months ago through the Humble Bundle, and it's been pretty cool so far. Looking forward to seeing how it develops.
And with that, onto the list!