Agree, Thailand, Philippines, Vietnam, Cambodia all good with slight differences.
Alcohol extremely cheap in PI and Cam, if you're a serious drinker they are the place to go.
Sightseeing and touring, Vietnam wins hands down.
Thailand has the cheapest accomodation and women.
Easiest to stay in Philippines, next Cambodia, then Thailand, and last Vietnam which has no long term VISA (unless you marry a local).