While I was in Patong last month I was lucky enough to be taken to two really great Thai restaurants.
Baan Rim Pa located on Phra Barami Road. The place is located on a cliffside an offers a spectacular view of the ocean (great place for those with a date). The Naam Prig Goong Siab (Dip with dried shrimp - Phuket Style) seemed to be the dish of choice as almost every table had ordered it.
Another restaurant I found simply incredible was a little mom & pop Thai place also located on Phra Barami Road. I don't know the name. Starting on the corner of Bangla Road, if you go down Rhat-U-Thit Songroi Pi Road and take a right on Phra Barami Road it is located on the right hand side maybe 30 meters down. All I can say is bravo for this place! I went here several times with some Thai friends and the food they ordered was just oustanding (some of the best food I've ever eaten). This place usually doesn't open until the late afternoon, but it's open until very late. A great place for one of those late night meals.
Using the map link above it would be located in grid B.
Highly recommend a visit if you get the opportunity.