Everyone should go to the Beach House once for dinner. However, we found dinner to be kind of a zoo, with half the restaurant getting up and running outside for photos with the sunset. It just was not a relaxing evening. We now go just for the Li Hing Mui magaritas and pupus on the bar terrace. If you are there at 5PM you can usually get a table, and it is not as crowded and rushed as the dining room.
We were at the Kauai Coast in Kapaa for the first four days of our Waiohai/Kauai Lagoons weeks this month, and I checked Yelp for a place to eat our first night. The Eastside, in Kapaa had excellent reviews and proved to also have excellent seafood. (all always locally caught) We had wanted the ono, but due to the weather they had not been able to get it that night, but the mahi mahi on coconut polenta was absolutely perfect, and my husband's prawns were fine, just not as fine as the mahi mahi. Best I have had, better than Beach House or Roy's. Prawn and scallop spring rolls were amazing and the mango cheesecake couldn't have been better. It is not a "destination" restaurant for view or decor, but the food at dinner is equal to what we have had at The Beach House. It might be a bit less expensive than the Beach House, and has a much more relaxed atmosphere. They had two Hawaiian ladies singing and playing, have music most nights,and most other customers seemed to be local that night.
We meant to go back, but once at Waiohai, never were back in Kapaa with time to eat again. We will go back next time!