You haven't played an iPhone or a Touch have you?
If you need a phone, or a top notch personal media device, or both, you can't go wrong with Apple's wonderful portables... BUT for gaming... BLAH!! Trust me, it's not that good, but maybe you only like "casual" games.
The only game I play daily is Sol Free. I bought a game called Blue Attack which is good, but it would be better with an actual d-pad.