The Arunras Restaurant is part of the large Arunras Guesthouse. It is one of the few restaurants in town but it is a good choice. It has an extensive menu, good food and service, and is reasonably priced. We ate three meals there. The buses going to and from Phnom Penh and Siem Reap stop at the Arunras Restaurant. I think that there were two different dining areas. We always ate in the smaller one (maybe the prices were better). A typical meal was 2-3 USD.
Don't say no until you try them. The crickets turned out to be quite tasty but the beetles were too crunchy. Cooked, spicy bugs are not cheap though; what we got cost 4 USD. BTW, you remove the large cricket legs before eating them.
Favorite thing: I had found this reference about the Royal Road and an excellent guide, Sophy Has, before I went to Cambodia in 2010. I emailed Sophy but he did not answer until after my trip was already over. It turned out that he had been on an extended trip into the jungle and had no phone or internet service until he got back to Kampong Thom. He even apologized for not getting back to me sooner, but it really was not his fault at all. Although I have never met him, I get the feeling that Sophy is a really nice person and I definitely plan to contact him when I go back to that part of Cambodia to visit additional remote sites.