I recommend Fiji's tiny outer islands. Specifically barefootmantafiji.com. Fiji Airways is cheap enough, and you can get a free stopover (with $100 added taxes) on the way to SYD or CHC or many other destinations. Much, much cheaper than Hawaii and unforgettable.
Maybe I'm paranoid, but if I'm going that far into the middle of the ocean, I'd rather be on U.S. soil in case anything happened.