Originally Posted by EuropeanPete

If you base yourself on Koh Samui and are comfortable not always being in 4/5* chain hotels, you could do worse than to pop over to Koh Tao for a couple of days (<2hr speedboat) where Sairee Beach is incredibly beautiful (and with lots of bars and restaurants). Alternatively, less than 40min away from Samui by private resort speedboat you have the Anantara Rasananda on Koh Phangan which has beautiful villas on a stunning (small, relatively isolated) beach.