We stayed at the Seda Villa in Siem Reap for two nights to visit the temples. We has a very positive experience and felt that we were getting genuine Cambodian hospitality. We ended up relying on the owner Sam for a lot, and he was incredibly helpful, organising a two day bike tour for us, helping us to get our washing done cheaply, and generally making our stay as comfortable as possible.
The Seda Villa is more a guest house than a hotel, but was one of the best places we have stayed in on a 5 week tour of Asia. The rooms (pink and yellow) were very comfortable, the pool nice and refreshing, the breakfasts big enough to satisfy some demanding appetites, the internet was good and the service was very friendly. To give you an example, Sam had figured out from our passports that it was my son's birthday on our second day there, and a cake with his name on magically appeared at tea time.
We had 48 hours to see the temples, and with very little notice, Sam organised a cycling guide and some bikes for us. It was a great experience and really good value. We rode around 20km each day and saw most of the temples including some that were hidden down jungle paths, and cycled on the top of the wall of Angkor Thom - an amazing experience.
All in all highly recommended, a lovely place with a personal touch in a town that seems to be being overrun by sprawling, impersonal hotels.