What bus do you get to get from bangkok to Saigon?

There is not direct bus that will bring from Bangkok to Saigon. You can either go by plane or hired a car or private transportation to get there, but more expensive and time consuming. But if you really want it that way, it could be done if you are prepared to pay the amount they'll ask. Or, from Bangkok take a bus to the border to Laos,from there take a bus that will bring to the city of Laos, and from there, you can take a bus going to the border of Vietnam and the take another transfer and you can go to Saigon.