Favorite "expensive" iOS game

[actionrpg8000]

I have arrived somewhat late to iOS gaming. Prior to getting my iPhone last October I did all my gaming on a psp or ds (obviously I enjoy mobile gaming). Being used to mainly psp gaming I was surprised by iOS pricing structure, which seemed to relate anything over $1 as expensive.
I am interested in what people's favorite "expensive" iOS game is. I recently bought Starbase Orion for $7.99. I was impressed that the dev stated it would not go free, and has had no sales after the intro sale, which was over a year ago. The game is phenomenal, and I wouldn't have batted an eye at paying over twice the price for a similar game on the psp.