Whenever I have friends visiting from the mainland, I almost always take them to the Polynesian Cultural Center. It should be a destination for all tourists visiting Hawaii. Be prepared to spend a day or at least half a day there, as the Center is filled with lots of information on Hawaiian (also, Tongan, Samoan, etc.) culture and amazing sights. Entrance fee is about $30, which is admittedly a bit pricey; however, if you spend a long time there and catch the amazing shows, it is well worth it. Some shows you definitely should not miss are the hilarious tree-climbing show (where performers climb trees at amazing speeds and joke hilariously with Japanese tourists), the amazing flamethrower show (where performers do all sorts of tricks while spinning sticks with the ends on fire), and the marvelous canoe-pageant (complete with hula, singing, etc.). The Center also houses some Hawaiian artifacts and aesthetically-pleasing replicas, which provide loads of picture-taking opportunities.