Oahu's tourism center, Honolulu -- specifically, Waikiki Beach -- is filled to the gills with touristy shops, chain restaurants, fast food spots, malls, traffic, high-rise hotels, and vendors hawking cheap seashell jewelry and T-shirts. It may be decades removed from the unspoiled tropical paradise that many mainlanders associate with Hawaii, but there are a few posh retreats that serve as elegant oases amid all the beachy hubbub.