Personally, I'm not super picky about socks, so I buy whatever moisture-wicking socks are cheap at Kohls. My one requirement is that they have the heel tab, which I think helps with blisters (that may be a placebo effect, though). I do have a pair of Feetures merino wool socks that I love for winter runs and races, and I'm probably going to pick up another pair of those soon. So if I had to recommend a brand, I'd probably say Feetures ... but I'm really not picky.