Travel tips to share on Cambodia?

I have traveled to Cambodia once, basically to see Angkor Wat. Despite my being so bored with all the Wat (Temples) that I had already done in Thailand, this was an amazing site to see. Even though am not much of a sight-seeing person, I actually enjoyed this, especially if you know some of its historical background. Unfortunately, I cannot tell you much about how to stay there on a budget, as we did just an overnight trip or not even, we were basically based in Thailand and just did a drive to the border and crossed over for a day. This was several years ago, and I heard it has changed a lot, so I am even planning a return trip, though this time I would be including Vietnam in my travel plans.