Just happened to remember this old thread and thought I'd put my 2 cents in. I have foot problems caused by diabetes. I have to wear "special" socks. There is a store near my house called "Foot Solutions" that specializes in footwear for persons with foot problems.
I buy a sock there made by a company named Drew. They have an extra padded sole and heel but are extremely loose on top without being saggy. They are made not to cut off circulation. Also, they have the seams on the outside of the toe, so there is nothing to rub on your toes.
They come in white or black and cost about $11
pr., but they're well worth it to me. BTW - they also make a dress sock in black that is a little thinner but made with the same features. They are easily the most comfortable sock I have ever worn.