I don't mean to blow Jason's trumpet but, when I bought my HC ties, he gave me a pair of ribbed Pantherella socks. When they arrived I was most skeptical. They are wafer thin cotton socks. I thought they would quite literally disintegrate after one wear.
Anyway, I had also bought some 'cotton rich' socks from Myer. After about 4-5 washes, the Myer socks have started to 'pill'. The same number of washes for the Pantherlla socks has had no effect on the sock at all. The ribbing is still 100% new. It is quite incredible.
The only problem is, I am a big fan of thick socks. Pantherellas are anything but.