Used to live on Oahu.
Good call on Alan Wong's. That place is awesome.
Sushi Sasabune is amazing too. Moving to Hawaii, I thought I was going to have the best quality sushi everywhere. Then I found out that most sushi fishes (tuna excepted) weren't from warm water climates. Sasabune ships in all his fish from California & they brag about it. His food is incredible though. By far, the best sushi in Hawaii. The most memorable piece was a whole piece of monkfish liver on sushi (not monkfish liver pate) that was charred with a torch. Almost dropped me to the floor it was so amazing.
Someone also mentioned KC Drive Inn. Search that out & get the chocolate, peanut butter ono ono milk shake. It is sooooo worth it. Anybody I'd ever taken there couldn't get over it.
One other place that nobody's mentioned yet is Side Street Inn in Honolulu. It's a total local hangout but they have some of the best food on the island. When David Rosengarten was there doing a Food TV show, he even asked the audience if they'd had the deep fried pork chops at Side Street because they were so awesome & everybody went crazy. Got to get the deep fried pork chops, misoyaki chicken (we always ordered no skin), the big island smoked pork & maybe some fried rice. Just incredible.
Last one I'll mention now is Maple Garden. Chinese restaurant with incredible won ton noodle soup & Chinese donuts. Man my mouth is watering just thinking about it.
Ready to book a trip back!!!