The ruins of Angkor Wat, Angkor Thom and their surroundings spread around Siem Reap in Cambodia belong to the so-called Khmer civilization. Among the many UNESCO World Heritage Sites, it can be considered as one of the best.
This WEB-site was created based on a trip to Siem Reap for about two weeks in August 2013, and my visit to the Angkor ruins using a tuk-tuk (motorcycle taxi).
I think there is no one who visits Angkor ruins without visiting Angkor Wat and Bayon. However, there are some other ruins that we recommend. Even though I didn't know the names of the ruins until I actually visited them, there were many places that I thought were worth seeing. Please use this site as a reference to build your own trip to the Angkor ruins.
To visit the Angkor ruins, I recommend a private tour rather than a packaged tour from your country. There are so many local tours available for every corner os Angkor Ruins.
Online admission ticket for Angkor Wat (Angkor Pass)
An admission ticket, so-called Angkor Pass is required to tour the Angkor ruins. There is just one ticket counter available. So I recommend you to purchase Angkor Pass online (online purchase from here).
There are 1-day, 3-day, and 7-day tickets. The 7-day ticket is further divided into a 7-day ticket and a 30-day valid ticket. If you buy a 7-day ticket, I think it's a good way to visit many ruins at your leisure.