There aren't hardly any; RPG's and Action-Adventures unfortunately cost more to develop than average App Store prices allow (and lack of a true d-pad/joystick makes Zelda games hard to do). Vay is a good one, a port of an old Sega Genesis CD RPG. And Chronicles of Inotia: Legend of Feanor fits the RPG category, though it's a bit more old-school than Golden Sun.