One restaurant in Patong that you will here a lot about is the Baan Rim Pa. I have dined here a few times, they really serve some pretty good classic Thai cuisine, please be aware the place is quite pricey and you get what you pay for. Now if you are looking for a romantic place to dine, this is a good choice, the restaurant overlooks Kalim beach so you can't go wrong with the view.
Final words, good restaurant, high prices and excellent open air feeling with piano music to boot.
Yes Keith, I think the ambience and service are fabulous here, the food is good, but not the best Thai food in Phuket. A little pricey, but worth it for the atmosphere.