The best socks I've worn are Teko summit series Marino Wool socks. Seriously comfy and warm. Bear in mind that they are seriously thick, so you need room in your boot for them.
Yesterday I bought another Icebreaker Marino Wool base layer top, 260 grade. I've already got a lightish 200 grade one, but I've decided to get the heavy 260 grade one for winter hill walking. Obviously this will get used on the bike come the spring. Not cheap at 75 quid, but it will last many years, and can be worn for days, if not a week or two without getting too smelly. And they are seriously warm.
And if like me, you hate wool, well forget all your preconceptions about wool, Marino Wool is absolutely heaven worn against your skin.
http://www.tekosocks.co.uk/http://eu2.icebreaker.com/on/demandware.store/Sites-IB-UK-Site/en/Home-Show?Locale=enPolar Buffs are great too, ideal for keeping yer neck and chin warm while stopping the draft going down yer neck.