I voted Maui because that's the only place I've seen in Hawaii other than Honolulu (and all around the island) where I used to visit for work pretty regularly. Check out the north shore for big-wave surfing if the curl is curling high. Bring binoculars and a large thermos full of Mai Tai.
Lunch, fresh fish dinner and cocktails at Kimo's is hard to beat; see Iao Park and the famous Iao Needle. Take time to get away from the beach/resort scene and ease around the jungle a bit. You need wheels. Too cool. Maui is a beautiful place but it's only a tourist trap/resort-without-culture thing if you never get past the Sheraton parking lot.
http://www.kimosmaui.com/
http://www.hawaiiweb.com/maui/html/s...tate_park.html