Tahiti Nui has the best Mai Tais on the island and is right next to the best hangover breakfast too!
Tropical Taco in Hanalei is good. Solid choice. Good lemonade. It used to be just a van, now they are to the right as you drive into town.
Sushi Blues in Hanalei .. nothing to crow about and you have to listen to live 'blues' while you eat your manhattan priced sushi. . .
Pau Hana Pizza in Kiluea . . .used to be pretty awesome, but I did eat at the best pizza places in Brooklyn in the past 2 months, so maybe I'm just more judgemental. They have a crust to topping doneness issue. Crust undone, topping cooked. Actually, come to think of it I find this a problem nationwide. Maybe ask them to make it well done and the crust will be okay. The pizza with pineapple, ham and chipolte is the best one.
Hanalei Pizza. I've only been there twice, but they will make a pizza for you to bring home and cook. They are also really nice .
Bar acuda or Baracuda in Hanalei. Tapas. Fine wine list. Nice desserts, great dessert wines. Extremely expensive for Hanalei. The host staff acts like you are trying to get a seat at Babbo at 7 on a Saturday. Avoid.
Lepperts in Princeville next to Foodland. Ice cream. . . do not avoid. go now. Buy a ticket to Kaua'i and go there . . . now. It is the kind of ice cream that makes you unable to sleep if there is any in the freezer at night.
Banana Joe's just outside Kiluea. . . good produce. They have mint growing out front that they let me pick for free.
Foodland Groceries (Kaapa'a vs. Princeville). . . Specifically Poke. It is good if you buy it in Kaap'a. Cheap and tasty. It is basically a tradition that I buy it first thing on the way to the house from the airport and eat it in the car. When purchased at the Princeville Foodland there is a good chance you will get ill from eating it.
Princeville Resort. . . The best place I have ever been for cocktails at sunset. Brunch is also nice. The New Years Eve party is pretty good too, although slightly more conservative a party than I would generally enjoy. Lunch and dinner are fine with a much better view and nicer staff than Baracuda for the same price. They do not scowl at you if your kids are running around like manicas.
Safeway (in Kapaa) is lame and more expensive than Foodland.
Fish Taco Van at Annini Beach. . . good. nice location. Just head to anini beach on the 'no outlet' road and the fish taco dude is usually parked around the picnic area. Buy the tacos and then drive to the very very end of the road to eat them.
Kihuea Fish Market. . . pretty much the best bet on the north shore. Fresh, good, laid back, nice location. Good for kids, good without kids. The poke here is far far better than foodland. The mahi mahi sandwich is terrific. It is just across from Kong Lung in Kihuea.