I love the Gymbo socks. We have a polyester allergy here, so we're limited to those socks that are cotton/nylon instead of cotton/poly. Of those, the gymbo ones are the best. They're soft, comfy, and they stay on.
Target used to have great socks, but they switched to cotton/poly about a year ago, so we had to stop buying them.
S, mama to my Second Grader, K (9/07) and my Kindergartener, e (7/09) and married to my best friend, E (2007)