The Racha , Koh Racha
The Racha's 70 villas have been elegantly designed to blend in with the environs of Koh Racha Yai – trees even grow through some of the rooms. Nature walks and snorkelling are the main draws of this diver's haven just off Phuket, but the resort also offers a spa, yoga pavilion and four dining options. For the ultimate view, book the five-story lighthouse, with its circular top deck.
The Racha, Batok Bay, Koh Racha Yai, Phuket (00 66 76 355 455; theracha.com). Doubles start at 8,142 baht (£148), including breakfast.
Costa Lanta, Koh Lanta
With contemporary architecture set amid tropical gardens, Costa Lanta strikes just the right balance between modern design and a tropical escape. The rooms are set back from the coastline amid the trees and are decked out with poured-concrete and timber walls and a partially open-air bathroom.
Costa Lanta, 212 Moo 1, Saladan, Koh Lanta Yai, Krabi (00 66 2662 3550; costalanta.com). Doubles start at 3,025 baht (£55), including breakfast.
Paradee, Koh Samet
The small island of Samet is a national park, peppered with dazzling beaches either side of a forested ridge. At its narrowest point in the quiet far south, you'll find Paradee, opening onto the east and west coasts of Ao Kiew. The 40 villas are luxuriously furnished with teak, rattan and Thai silks and most come with private pools and Jacuzzis.
Paradee Resort, Ao Kiew, Koh Samet, Rayong (00 66 38 644 283; paradeeresort.com). Doubles start at 17,800 baht (£322), including breakfast.
Zeavola, Koh Phi Phi
Brought to fame by Alex Garland's novel The Beach, Phi Phi is firmly on the backpacker trail. But the beaches of the north are largely unspoilt and this is where you'll find Zeavola, the island's only five-star hotel. Each villa has a private garden, and the rooms are adorned with hand-printed panels and batik.
Zeavola Resort, 11 Moo 8, Laem Tong, Koh Phi Phi, Ao Nang, Muang Krabi (00 66 75 627 000; zeavola.com). Doubles start at 11,770 baht (£214), including breakfast.
Six Senses Soneva Kiri, Koh Kood
Opening in the spring, this is set to be one of Six Senses' most expensive resorts. It has been designed to protect the island's unspoilt beaches, rainforest and waterfalls. But don't expect rusticity. Rooms have private pools, and facilities include astronomy lessons, a sting-ray-shaped den for children and the option of dining in the treetops.
Six Senses Soneva Kiri, Koh Kood (00 66 2631 9777; sixsenses.com/soneva-kiri). Doubles start at €1,473 (£1,228), room only.