Trenched aka Iron Brigade - My favorite of all these action/TD games that have been surfacing lately. And it just got a new content patch.
Shadow Complex - It's been mentioned a lot, for good reason. If you liked Super Metroid, you'll like this.
Hydro Thunder Hurricane - It's as fun as the original, with prettier graphics. And the DLC is actually worthwhile.
Rez HD - I have bought this game 3 times. I would buy it again.
Bangai-O Missile Fury - If you think Dark Souls is the hardest game that came out this year, you'd be so very wrong. It's awesome though. Takes the action of the Dreamcast version and some of the puzzle-ish focus from the DS version.
http://www.youtube.com/watch?v=NMISF47j-lY
Multiplat stuff:
Hard Corps: Uprising
Castlevania: Harmony of Despair
Castle Crashers
Edit: HOW COULD I FORGET AFTERBURNER CLIMAX