In 2014 I did fly from Khon Kaen Airport to Don Muang Airport in Bangkok. As flying from Khon Kean to Bangkok has now become cheap with now 4 airlines flying this route I have become very easy to go to Bangkok just for a day. So I had a look what airline would be the cheapest for the day I wanted to go. And this time it was Air Asia. Of course you have to be careful for unexpected add-on's when booking online. They still did get me with a surcharge of about 100 Thai baht for using my credit-card. But the flight was good, friendly staff and smooth flight. The only thing is there is no free in-flight service. Not even a drink. But for 1.600 Thai baht return-flight I do not have any problems with that. So I would not hesitate to fly Air Asia again next time. For more information see Air Asia (English)