I used to swear by Smartwool but now use Darn Tough. They're the only sock company I've heard of that has a lifetime guarantee AND has a product that is comfortable enough that you'd want to take em up on it.
Like smart wool, there are a lot of models to choose from according to your needs/taste.
I've all but switched to Darn Tough too. I still have 1-2 pairs of SmartWool socks that I'll wear until they wear out. I have used liner socks from REI and Cabelas and found both to be about equivalent. I only wear them when I'm doing a lot of hiking/walking though. Sitting I wear insulated boots with a single pair of insulated socks. I find that if I try to wear multiple pairs of socks it just chokes my feet and they get clammy and ultimately cold.
