The easiest and fastest way to reach Koh Samui is by air from Bangkok, Phuket or Singapore with Bangkok Airways, the only airline to serve Koh Samui.
Samui airport must rank as one of the most beautiful in Asia and further. Its tropically planted gardens burst forth with flowering glory and greenery, year round.
You can also get to Samui the water way. From the mainland you can catch ferries going between Suratthani and Samui every hour in the daytime.
There are also speedboats, ferries and catamarans taking you between the islands of Koh Samui, Koh Tao, Koh Phangan and the mainland.
A 50-kilometre ring road skirts Samui's coastline, giving ready access to all beaches and the little administrative center of Nathon with its beachside huddle of houses, shops and restaurants. The best and safest form of transport is a self-drive air-conditioned vehicle (car or 4 wheel drive jeep); motorbikes can also be hired (be cautious of traffic hazards and wear a crash helmet). You then have the freedom to explore the island and its treasures at your own pace.
You will find a choice of international brand names such as AVIS and Budget as well as local car and motorbike rentals.
It takes about an hour to drive around the island if you don't stop along the many beaches or take some of the side tracks (all of the rough trails crossing the mountainous interior are strictly 4WD or dirt bike trails).