I only buy Hanes socks.  The non-skid bottoms are great and they fit well and stay on.  My son has pretty big feet so I buy a couple sizes up from his clothing size (he wears a 24 mo clothing and I am now buying the 4t socks)  I accidentally bought these crews instead of the lower socks this time.  They don;t work as well on chubby legs but they can be folded down and work fine that way.