When I was engagement ring shopping I went to Nazars just to get a feel of what I wanted to purchase for my fiancee. I found the sales staff to be very helpful, and the selection is very good. They have a good stock of diamonds and rings by many designers.
I did not end up purchasing from Nazars, because I thought there prices were a little high and I didn't want to have to haggle. I went with an internet retailer instead.