Definately go to the floating markets. You have to get up early but its amazing.

I have been to both. There is a lot to do there. Just be cautious around the nightlife. Nothing there starts in the morning, everything in Thailand starts around noonish and goes till the wee hours of the night. Everything there is fairly cheap, I recommend you get some food from the mom and pop restaurants, I did and it was great. The people are very friendly and love Americans (many for our money). If you try to speak their language, they will love you for it, and if you make friends with the street vendors they will usually hook you up with better prices. Understand too, that it is expected for you to try to talk them down on the prices of street goods. Shirts, trinkets etc... are all overpriced when they see "falang" (white guy) coming. Nothing is marked either, so shop around and try to talk them down. If you don't get the price you want walk away, they often times will come follow you and try to compromise. It usually ends with "special for you". Try not to kill them on the price you pay though, the street vendors are often dirt poor and you may be the difference between a sale or no sale for the day. It is up to you where you go while you are there, but Pattaya beach is nice and Bangkok is too. Bangkok is very crowded though. If you can sneak off to Phuket, or Chang Mai, everyone I know who went there love it. Have fun, it is a blast.