We visited all the beaches on Koh Samui and I liked this the best. 15 mins from our hotel in Chaweng - this beach isn't as big but it is a lot less crowded than Chaweng. Lovely beach. The sea shelves away quite quickly but having nearly drowned in a rip tide at Chaweng, we stayed in the shallows.
Lots of restaurants, cafés and shops - we really like it here. It was very relaxing. Options to do water sports if you wanted etc. No complaints at all. Would highly recommend it.