Ta Prohm is the one temple that has been left essentially as it was "rediscoved" at the end of the 19th century by the French. Huge fig, banyan, and kapok trees have grown thoughout the temple monuments, their roots often splitting open sculptures and walls to surreal effect.
This temple is where movies such as "Tomb Raider" and "Raiders of the Lost Ark" were filmed. You just keep walking through and saying "amazing" and "can you believe this?"