Nicest vs. cheapest Hawaiian island (for vacation)?

From my experience, your best deals are packages including airfare, hotel, and car rental on expedia. I've found similar rates on other sites but never anything cheaper. If you go that route you can find an affordable deal for any island. For all islands except Oahu, a rental car is a must, and it's good for Oahu too if you can get one. Oahu is the cheapest island. Kauai and Maui are the most beautiful (although Oahu's got some real nice parts too). Kauai is the most beautiful island in most people's opinion, and I'd agree. Don't miss the Na Pali coast by Zodiac boat tour. Worth every penny if you go in the summer.