I just got back from Princeville. It was amazing!!! The island of Kauai is a must!! Just rent a car at the airport & drive! If you decide to stay at Princeville go check out the little town of Hanalei...its where Puff the Magic Dragon is from ;) A few other must sees are Kilauea Lighthouse, Waimea Canyon, Napali Coast (by heli) and the Queens Bath.
http://www.hawaiiweb.com/kauai/html/...eens_bath.html
On Oahu, I didnt like Wakiki at all, way too touristy. Try the Kahala Mandrin Oriental, its out of this world!
http://www.mandarin-oriental.com/kahala/
You can rent a car right there at the hotel. Take a ride on the Kam highway & back down 99 to Pearl Harbor!!