*Siem Reap (map) — access point for Angkor Wat and various other attractions in the north. *Kampong Cham (map) — nice countryside village on the Mekong river and good place to meet real Cambodia.
Cambodia has international airports at Phnom Penh and Siem Reap >> corp.cambodia-airports.aero.
Most Thai buses run to but not across each of the crossings. Exceptions include the direct bus services from Bangkok to Siem Reap and Phnom Penh, run by the Thai government bus company.
BUS: Avoid VR Express and Phnom Penh Sorya Transport Co. They have a history of threatening customers, manipulating, lying, and being unhelpful and rude. They prioritize cheating passengers of their money.