The Wind In The Willows I remember reading with rapt delight in 2nd or 3rd grade, and I liked it so much I gave it to my brother Sean two Christmases in a row when he was roughly that age. I've noticed how awfully children's books get abridged and bowdlerized.
I'm still trying to get Sean and Lucas to read and appreciate "Huckleberry Finn" in it's original form. Hell if any of you all haven't read Huck Finn yet, drop what you're doing and get a copy. Twain invented the modern American Novel, and if someone has topped him since, I've yet to read it.