Phuket Island

Where you base yourself here matters more than almost anywhere else in Thailand. Patong is the loud end, with beach clubs, nightlife, a dense strip of everything aimed at tourists. If that's not your vacation, don't book it and then complain. The quieter coves elsewhere on the coast are better for actual swimming and doing very little. And Phuket Town is a different island altogether, with Sino-Portuguese shophouses, local markets and Thai food that isn't priced for resort guests. I'd give it at least a day, even if you're here for the beaches.

Most people come for the water. Snorkeling, diving, jet skis, boat trips out to the Andaman islands and dive sites, all of it easy to arrange once you're on the ground. The island works well as a base for day trips rather than somewhere you need to stay put. Inland there are temples and cultural sites if you want a break from sand.