We go to Kauai every other yr. with our timeshare, the rest of the time we cruise and sightsee and always in the go so this my relaxing time. We have done everyrhing on the island but the best and very reasonable place to eat is KEOKI'S PARADISE on the Poipu side of the island. Great food get there early to make your reservation you can go shopping it is in a mall area. You won't be sorry have fun
There is a little place north of Princeville... complete whole in the wall, but totally awesome. The locals absolutely love it, and I can vouch for the food. The place is called Red Hot Mama's, they make tacos and burritos of all kinds. The place is walk-up and order, there is no dine in option. You can find it on the main road, north of princeville, approximately 1 - 2 miles just before the road ends in a dead end. Visit one of the many beaches on the north side of the island and hit up Red Hot Mama's for lunch one afternoon, you won't be dissappointed.
Also - for an absolutely amazing way to view the Na'apali coast, check out Captain bob's catamaran excursions, which leaves out of the South/West shore. You won't be dissappointed, we got to snorkel and swim with sea turtles and had many dolphin sightings along the way. Absolutely amazing. A helicopter tour is another amazing way to see the Na'apali coast.
Two of our favorite restaurants are Duke's at the Marriott and Beach House Restaurant in Poipu. At Duke's you can go casual at the barefoot bar or eat upstairs for a nicer dinner. We go to the Beach House on every visit to Kauai, usually that last night there. It is ocean front and good food. Actually both Dukes and Beach House are ocean front. Try to schedule the Beach House at sunset, it's beautiful and makes for a great photo op also. Also there is a great little place in the Poipu Shopping Village that serves great brats and hot dogs with unique toppings. Sorry I can't remember the name and we have been there several times!
The name of the place where you get the hot dogs in Poipu is called "Puka Dogs" they are really great. I go to Kauai every year and we make sure we have a Puka Dog each trip. We love the Mango and mild toppng. I agree that "The bare foot bar" at the Kauai Beach Club is a great place for lunch or dinner, run $15 per person. Make sure you have a Hula pie for desert (you will want to split it). If you want to eat good food where the locals go try "The Bull Shed" in Kaapa. The fish and prime rib is great. Hard to find but alot of good food, not much on decore.