If you're a thrifty shopper, your best bet is these UGG Socks. It's a popular item, while not very pricey. In this price range, you can also check out these Richer Poorer Socks. It's also a popular item and won't break the bank. You might also want to consider these adidas Socks. The price is very reasonable, but the effect on your wardrobe will be pretty fantastic.
If you can afford it, then you won't be disappointed if you check out these Sonia Rykiel Socks. It's an expensive but smart option.