What are some cool games for the ipod touch?

I heard that the app flash cards are useful. And the moron test was a lot of fun. what else is cool. Let me know what and why. Thanks A lot.|||shotgun. i believe there are two games similar to this and they are both entertaining, though admittedly simple.|||i love the game x-plane flight trainer and the best part is is that it's FREE!! (YAY)|||i shoot it doesnt get repetitive its fun and only 99 cents for a limited time