An iPhone game worth "premium" price tag: Civilization Revolution
I picked up Civilization Revolution for the iPhone over the weekend for $5. Totally worth it. $5 is on the higher price end for iPhone games, but its essentially a straight port of the Nintendo DS version. It has all the things that made Civilization Revolution great on the console, just on a smaller screen. If you are a Civ fan, I strongly recommend it. Be warned, though, it eats through the battery pretty quick.