My home is in Thailand - but for work purposes the last few years I have been back and forth/in and out of the country a lot.

Best bet for internal flights are all on line. The low fares last year to Phuket on TG were to help get post-tsunami travel back up.

I use nokair.com and airasia.com almost exclusively.

BUT! If you need to be on time for a connection go with either TG, Nok, or Bangkok Air. Air Asia has a terrible on-time record. My last two Air Asia flights were 60 and 105 minutes late departing.

AirAsia's website is sometimes a bit quirky too - leaving you wondering if you are really booked or not. I'm currently waiting for a refund when I booked elsewhere as their website burped when I tried to finalize details - only to find the next day that I have been billed and ticketed.

Don't wait to book here - all the cheap flights will be full (usually).