I was there for a little over 3 weeks. LOVED LOVED LOVED the islands, hated Bangkok.
If you are adventurous and have a wild side, I would certainly recommend it. I would travel alone or with someone you know would be a good travel partner (similar interests, flexible, open-minded, etc..) There are SO MANY other travelers to connect with if you do travel solo. It is inexpensive to travel once there, but be prepared to haggle over the price of just about everything (something I was totally unprepared for). I would return, but only to the islands ( I went to Ko Samui and Ko Phangan in the Gulf of Thailand). Good times!