smartwool is the best!
i wear them on hikes, and my husband wears them every day.
i own two weights. one is heavier, for cold-weather stuff like snowshoeing, skiing and the like (we're at 9000 feet northern new mexico), and the other is a "base layer," which is ultra thin (to wick sweat and prevent rubbing on long hikes).
so when you say "lite hikers," that's what i think of. and those base-layer socks probably require something smaller than 0.
hope that helps!