My list so far is as follows:
Puzzle Quest 2
Rogue Legacy
Don't Starve
Ys I&II
Wanderlust: Rebirth
Dust: An Elysian Tale
The Testament of Sherlock Holmes
I've been hooked on Puzzle Quest 2 (not as good as the first one or that not-quite-sequel space hexagon one) and Rogue Legacy, but I plan on getting to all of them ASAP, likely in that order. I meant to grab Scribblenauts Unlimited, but I forgot... Also planning on buying Civ 5 Gold Edition and possibly a few other games, but I'm waiting for a flash/daily sale first.