Ko Tao may still be the smallest in size but in many other ways it's grown up. The island is consistently gaining popularity and going more upscale, but for now this jungle-topped cutie has the busy vibe of Samui mixed with the laid-back nature of Pha-Ngan. But Tao also has its wildcard, something the others don't: easy-to-get-to, diverse diving right off its shores. Cavort with sharks and rays in a playground of tangled neon coral, toast the day with sunset cocktails on a white beach then get up and do it all over again the next day. But even while the island may be synonymous with diving, there is much more to the place. Hikers and hermits can re-enact an episode from Lost in the dripping coastal jungles. And when you’re Robinson Crusoe-ed out, hit the pumpin’ bar scene that rages on until dawn.