I have two pairs of awesome boot socks from Sox Trot. I have socks of this type from a number of manufacturers, but I love the Sox Trot designs -- over 50 styles of anklet, tween, and knee-high, with seasonal updates. Check out their store, with most styles about $8.99.
Which one do you like? I love the vibrant floral, but the green and black is cool too. Let me know which one you'd like by posting a comment, along with contact info.