The Kata Rocks Clubhouse is known as the best sunset and romantic restaurant in Phuket. It is open to the public, make sure to book in advance. The restaurant serves seasonally inspired Mediterranean cuisine featuring regional gourmet twists. While it's a bit expensive (around 500 THB per dish), and the food not the best on the island, the place, the ambience and of course the views make it the best sunset spot. Order a cocktail, take some selfies, splurge a bit, you deserve it :)