I used to love Gap socks and still like how they fit my foot; however, I think the quality is declining and i keep poking holes in the toes of the new ones. (And they are no longer primarily cotton, which is much preferable to synthetics IMO). I like Smartwool also but they are pricey. One benefit to smartwool is that a lot of their socks are sized. I have an average length (7.5-8) foot but it's narrow and low volume so a lot of the standard sized socks are too big in the foot for me. Gold Toe is usually OK for me too, if boring. (I like fun patterns on my socks inside my boots, because why not?)
I'm keeping an eye on this thread for recs. Will have to check out the Nordies' house brand line.