For Ngon Restaurant in Phnom Penh, I have three words,impressive, popular, and weird. This Vietnamese food has been run about a few months i guess, and been so popular among Cambodian, Vietnamese, and expat. There are not many restaurants in Phnom Penh put their food menu price in Cambodian currency, Reil, that is impressive to me that they are kinda respect Cambodia.
The atmosphere is superb and the price is very reasonable (10000 Reil to 16000 Reil). I find the food there is so yummy. I will definitely take my family there soon when i get a proper job :D
Being weird is not a bad impressive here. What i mean here is that why most of the restaurant stuffs are Vietnamese with fluent Khmer. If they do respect us for real, why not hire Khmer instead? :( Just my own view though, the rest is perfect.
For more detail about the view of Gnog restaurant you can visit this: http://nyampenh.wordpress.com/2011/01/23/ngon-restaurant/