Reputation and recognition vary greatly. A certificate that is highly valued in one country might be completely unknown in another. Start by researching the job market you are applying to. Read as many job ads as you can for Vietnam/Thailand and try and get a sense of what they are looking for. Ask questions on forums like this one (or ESL Cafe) of other teachers in that country to get their opinions on which certificates are the best bang for the buck.
A few things to remember:
1) there is an element of "you get what you pay for" in TESOL training;
2) there is no central accrediting authority for TESOL courses;
3) from a purely pragmatic perspective, a course is only as good as the job it will get you.
That's why, in my opinion, research is so key. Everyone is different. You education and experience combined with your goals make your choice of a course a unique undertaking. For some people, a shorter, cheaper course is the perfect supplement to their existing credentials. For others, a longer, more expensive name brand course (CELTA, Trinity, etc.) might make the difference on a resume lacking in experience and applicable education.
Here are a few places to start researching courses:
TEFL Board,
Which Course? and
Course Catalog.
Good luck!