The culture. The nature. The landscape. The people. And, of course, you're riep
The first place I visited in SE Asia and a great place to start a trip hopping through SE Asia. Locals really enjoy visitors, tourism is actually built into building their economy back up. A lot of local history to be seen that most don't even know went on in Cambodia. Temples, the Genocide Killing Fields (although sad you can learn a lot about Cambodian history there), and great places to eat.
The drinks are cheap. There's a dedicated tuck tuck all day. Me Mate's Place has wifi, geckos and it's damn cheap!
Great community and the locals are friendly. Pretty pricey for the tourists actually. You'll need to have great bargain skills to keep costs low.