Even though I have been to Bangkok close to a dozen times, I never tire of the Floating market in Damnoen Saduak. Yes it is touristy but it is also a photographer's dream location- color, shapes, food, people, handicrafts. It has it all! Make sure to leave time to wander around the town as well as along the river. Your hotel can arrange transportation - and some day trip companies even include some time on the canals in a boat so you get to see things from water level. This is one tourist attraction that you must DO.