I'm strictly an all-cotton girl, and my favorites are King Cotton by Wigwam. They're pretty thick, so you have to be sure your shoes are roomy enough.
DP Maddy, on the other hand, has fussy feet and swears by some crew socks we can find only in the women's sock section at Jocky outlet stores. They have really thick soles and wear like iron (so to speak). They are not all cotton and have some cool-max type of fiber in them. There is no brand name printed on the socks themselves (and of course the packaging is long gone) so I'm not going to be of much help in identifying them further. Oh--just dug out the receipt, and the numbers printed on it are 551274 white 9-11 783466143824. Two pair for $7.50.
You may already know the wisdom of changing your socks, and even shoes if possible, part way through your Disney Day. Really refreshing. Even when I'm wearing Birkentstock sandals I'll start the day with socks and then take the socks off part way through. Anything to give your feet a little change.
Janet