OUR TAKE: On the coldest days, this sock can be the difference between turning around and enjoying a winter adventure. Our tester gave it the seal of approval after a 10-mile, sub-zero snowshoe near Colorado's Hoosier Pass. "I was able to feel my toes for the entire day, a rarity for me," he says. "Plus, I was breaking in a new pair of boots and fighting through a foot of fresh powder, but I didn't get any hot spots, let alone a blister." The Denali is made of 91 percent merino wool, which traps heat and moves moisture, while 8 percent nylon lends durability (the other 1 percent is elastane). After a full winter of use, our tester didn't see any signs of pilling.

TRAIL CRED: "It's not very stretchy, but this sock is so thick that it holds its shape well and doesn't bag out over long days," our Colorado tester reports.