We're taking the oppertunity to travel from Bangkok to our Honeymoon destination of Chiang Mai to see a little more scenery. The scenery on the last third of the trip up into the mountains approaching Chiang Mai is particularly good, and even on the sleeper, watching the sunrise from the train in the morning is wonderful. And of course, the sleeper train itself is the scenery, a real Thai train with a chance to meet Thai people.
http://www.seat61.com/Thailand.htm#Bangkok%20to%20Chiang%20Mai