My son wore these brand new ones to his daycare for a day and they are already pilling quite a bit.
I'm not sure how well they will hold up over time. The small size suits him (he is 3.5 years old and weighs 31 pounds).
SKINS Unisex Essentials MX Compression Calf Tight
49 Review
Girls Winter Fleece Lined Tights Girls' Clothing
46 Review
Warm and Soft Wool Socks for Kids - Cute Animal Design, Thick Thermal Crew Socks for Children and Toddlers in Winter
43 Review
Jefferies Socks Little Seamless Organic Girls' Clothing
44 Review