Angry Birds - well, duh, it's what the iPad was made for ;)
Atomic Web - browser, way better than Safari
Zinio - magazines and shit, fuck loads of content, subscribe to stuff for less than paper
Tarot Pad - if you're into tarot and shit, I'm not, but fuck loads of people are, and when they get the death card I tell them they're going to die
Guardian Eyewitness - amazing photographs from around the world every day - hone your photography skillz!
SpeedtestX HD - free way to test the speed of your connection
Amazon Kindle - I bought my iPad as an e-reader, and you get all the Kindle books right here - better and cheaper than iBooks
Pinball HD - fucking well written pinball game, if ya like pinball
And, of course,
Nude iPad Babes - *ahem* have a wank in full screen ;-) <<-- I made that, so I'm giving it a plug ;-)
phew...