There is a bus that goes between the two - with a change of buses at the border. It's definitely the cheapest option, but takes a good half of a day. The easiest way to go is to fly - you can also get a visa upon arrival at the Phnom Penh airport. about 10 years ago
Flying takes around 1 hour...the bus, with the change at the border is a good half a day. It depends on your budget and what you want to do.
Bangkok Airways to a travel pass where if you are planning on flying more than 3 sectors, is great value for money - and can be used to fly into/out of Cambodia. about 10 years ago