After a recent trip, some thoughts:
Tahiti Nui (Hanalei)- Underrated,,,,At least when we were there (5 nights out of 9), they had fantastic entertainment starting at 7pm and we made lots of friends...You can order Tikiman pizza from the back, and once we had a Tahiti Nui entree, the Ono in a coconut, cilantro lime sauce with rice, that was excellent, worth the $20+ price.
Calypso (Hanalei)- the food is iffy, but you have to know how to order, plus they serve past the typical 9pm deadline in Hanalei. If you are a fried artichokes fan, their fried artichokes can make a meal if you're not starving and if you have a party of four or less, dining on their lanai is really nice.
Hanalie Dolphin (Hanalei) for lunch...being a fried 'freak', loved the fish and chips ($14). That day it was a Mahi fillet and while it was only one fillet and a little greasy on the outside, it was delicious. The fries were great too. My companions had the filet mignon burger and loved it, but pricey ($16).
The Chevron Station (Princeville) inside has delicious fast food, breakfast and lunch. They close from 3-4pm though.