The eight-hour bus from Thailand to Siem Reap is no longer a potholed, spine-adjusting experience. The newly-paved road provides a smooth ride to town.
If you are traveling to Siem Reap from Bangkok, try to avoid the overpriced and theft-prone buses departing from Khao San Road. Make your own way via public bus to the border crossing at Aranyaprathet (Poipet on the Cambodian side) which is only three hours north of Siem Reap.
After walking across the border and clearing immigration, team up with some other travelers for a taxi to Siem Reap. Nearly all traffic will be heading in that direction and there are many cheap options, including buses for only $10.
As with all border crossings, be aware of fast talkers who target tourists and offer "VIP" transportation or expedited visa service.
March, April, and May will bake you with staggering humidity and temperatures well over 100 degrees Fahrenheit in Siem Reap. The best time and populer months of November to February offer hot, dry afternoons and cool nights.
Kashif