I have been a smartwool fan for quite a while now, but the tend to run on the expensive side. When I was still in the Army, I always wore the old issued OD green socks. Wore them for almost seven years and never had too many issues.
Issue wool socks always worked well for me. Occasionally I would dab hotspots with Tincture of Benzoin and then put on a pair of nylon dress socks (nylon slides on the wool, tincture holds the nylon to the skin, wool warms up nylon does not transfer heat very well) make sure you dry your feet at every chance, nylon holds in moisture.