Kona Cafe is one of our favorite WDW restaurants, and we actually choose to have lunch there instead of dinner. We've heard lots of complaints that it gets very noisy at dinner due to people milling about in the resort lobby, but it has always been quiet and relaxing at lunch.
Everything that we've had there has been delicious. I'm not sure I'll be able to remember everything we had, but here are a few things I know we tried: Big Kahuna burger, Asian noodle bowl, Pan-Asian pasta, Island chicken sandwich, and Kona salad.
Don't forget to save room for dessert - the desserts there are fantastic!