Originally Posted by
Goldorak
No. The only airline flying this route is Bangkok Airways (PG), a very nice boutique airline. But you have to know that, due to their monopoly on this route, fares are quite expensive. They are not affiliated to any alliance but have code-sharing agreements with many airlines, including AF, Air Berlin. However, I think there is no code-share at all on BKK-REP. So you cannot earn Skyteam miles on this route but you can redeem Flying Blue miles on PG (but be prepared to give a lot of miles : 50,000 miles on FB for a return BKK-REP).
The monopoly is on the nonstop route, not on those involving stops in other cities. SIN is a better option to fly to REP if you must fly.
If you are not pressed for time, overland is now easier than it used to be as the road from Poipet to REP is now paved. Bus to Aranyaprathet and a taxi from the Cambodian side of the border is the best option for doing it overland. If you want to spend a bit more, you can take a Thai taxi from BKK to the border and then followed by a cambodian taxi,.