Originally Posted by hiyo

BKK-PNH on Air Asia, then a taxi, bus or boat to Siem Reap (tolerable). Or Air Asia to PNH, bus to Batttambang, then boat or bus to Siem Reap (less tolerable).

I have done the overland parts, although in the first case came to Phnom Penh from Saigon by fast boat, then took an express bus to SR. The second time flew into PNH from Kuala Lumpur on Air Asia, local bus to Battambang, slow boat to SR.

If tolerable also means quickly, then you are stuck with PG BKK-REP. It's a nice flight, but pricey, as you probably know.

If tolerable means not so quick, but willing to put up with a few inconveniences for the sake of the experience, well . . .