Games not yet mentioned here that are great or are extremely unique:
-Angry Birds Space. Significantly more fun than the original Angry Birds, some really nice experiments there.
-The Act. So much great craftsmanship, should probably convince the GB staff to do a QL. Don't watch the whole trailer if you're sold on it sooner than that.
-Squids/Squids Wild West. Sort of a marbles/tactics game. Personally, I didn't love it, but I know a lot of people who really, really enjoy it. I just didn't especially like the way the squids moves after you pulled them back; an iPad would definitely have helped, as I'm playing the game on an iPhone.
-Hero Academy. If you have a few friends on Facebook or Steam you can convince to play with you, this game is top of the line. Alternatively, Outwitters is available; I haven't really gotten the chance to play it yet.
-Dungeon Raid. It's a really clever puzzle game. I like it still.
-Tomena Sanner. If the review leaves you curious, check out the Quick Look.
Ziggurat!!! Ziggurat is a pretty cool iPad game.