Albert HD, iPad only (2.99 -> $0.99)
This game has been on sale in the past and even free. The same developer currently has all their apps on sale including MultiPonk HD. Both Albert and MultiPonk are really excellent.
Albert looks like a kids game, but I think kids of all ages will love it. The game is more like an art piece, but the included mini-games are actually very fun and use a lot of the platform's special capabilities. I think this is a gem!
Game Center: MarinasideSteve