Bangkok Airways (
www.bangkokair.com )
They have a lot of flights around SE Asia at excellent price points and are a great airline to fly with. Great staff, private lounges, etc. I believe they were voted 'best boutique airline', whatever that means!? lol (I think it is because they only connect tourist spots?).
They also run Lao Airline and Siem Reap Airlines.
The second time I was in SE Asia I got a 7-segment international airpass for $200 that I was able to use over a 4 month period to go in a giant circle around SE asia.
Claeren.