If you can afford the helicopter ride, I heard good things about it. The road doesn't go all the way around the island, so you can't see it all unless you rent a car and really hustle. If you rent a car and hustle, it is possible. Waimea canyon can't be missed. Hanalei bay is also beautiful, but you have to go really quick to catch both. If you give yourself 90 minutes to get back from Hanalei Bay to car rental return at the airport, that should be plenty of time. The island is small, so it is doable to get around most of the island. You just have to choose whether you want to see more and go faster, or catch less of it but relax more. Interested in becoming a travel agent? Follow this link to find out more. Home Based Travel Agent