In my experience, stay away from socks with any amount of synthetic material (nylon, rayon, etc.) unless you want stinky feet. Unlike cotton and wool, synthetics do not have sufficient wicking properties. This promotes bacterial growth which leads to smelly feet. Most cheap brand socks (and even expensive ones) have nylon in them. So pay attention to the tags.
Viccel has been mentioned around the forum. They have 100% cotton in two weights and also wool/silk blend socks. They offer 20% off for styleforum members. I have not personally tried them but am considering it. Anyone with personal experience want to chime in?http://eshop.viccel.com/