The original backpackers' island paradise has seen plenty of change over the past few decades. Sprawling development, western supermarkets and English-style pubs are some of the worst side effects; but the good news is that none of the buildings are - by law - taller than a palm tree, and the white-sand beaches are as beautiful as ever. At 15km wide, Koh Samui is big enough to provide pockets where you can hide from the crowds, with plenty of secluded coves and waterfalls to discover. In fact, if you want to combine classic Thai island scenery with some of the comforts and distractions of home, it's a pretty good bet.
For enclosed turquoise waters, head to Chaweng - a fringing reef keeps the sea calm and warm, and even in the monsoon season the northern part is relatively sheltered. The streets behind the beach are lined with rather tacky music venues, but the sand itself is silky-smooth and dotted with candlelit bars. If you're looking for a quieter beach, try Phang Ka at the southwestern tip of the island.
A boat trip to Ang Thong, which inspired Alex Garland’s cult novel The Beach, will probably be the highlight of your stay. There are 41 islets scattered like green teeth among the turquoise waters north of Samui, and most day trips allow you to climb to the top of the largest one for breathtaking views over the whole archipelago. You might spot dolphins (February-April), macaques, sea otters, monitor lizards, mynah birds and swifts; you could even dive with whale sharks, should you wish.
The reefs around Koh Matlang and Coral Cove offer excellent snorkelling. If you have time, we also recommend a relaxing day's snorkelling on the corals off Koh Mad Sum island, 4km southwest of Samui.
The island was made for rest and relaxation, so spend at least a day getting pampered and rubbed down. Most resorts have on-site spas, but in our view Kamalaya wins hands down for its serene ambiance and huge variety of packages and treatments (Conde Nast, Tatler and The Times all agree with us).
Hidden in jungle, the majestic cascades at Namuang are well worth a visit. They flow into natural pools that are perfect for cooling dips, so take swimming gear with you. The path up is a little slippery, and best negotiated on the back of an elephant from the nearby sanctuary. If you’re planning to go on foot, make sure you wear sturdy shoes.
Step back in time for a taste of old Samui, before the rampant development of recent years, at the pretty village of Hua Thanon. Bobbing fishing boats jostle for space in the bay, and the shoreline is crammed with market and street-food stalls. There’s also a butterfly park, a tiger zoo and an aquarium to visit.
Head into the Samui rainforest and fly across the canopy at tree-top level, on zip-wire cables of varying lengths. It’s a fab way to get a bird’s eye view of the jungle and see monkeys up close (plus you can let out a few Tarzan yells just for the heck of it).