I wouldn't spend much time in Bangkok, although the palace is pretty cool. I really liked Chiang Mai like they are saying, if you go on a Sunday night they have a huge market and you can get a ton of cool stuff. I went and rode elephants at a sanctuary and that was an incredible experience. I also went to the Tiger place. Most people say they drug the tigers, but I didnt think that at all. It was so cool. I really loved the Phi Phi islands. They are really unique and the beaches are incredible. If you go during the full moon, there is a pretty crazy party. Let me know if you have any other questions. There is a ton to do, and lots of fun to be had.