Glaurung said:
Well some of these aren't really fantasy, but:
Ayn Rand's Atlas Shrugged
or The Fountainhead
Stephen King's Eyes of the Dragon
Lord of the Rings trilogy
Lord of the Flies
for a great book on human nature-Obedience to Authority (short, but may be a difficult read)
-Mike Gill
Are you insane? Atlas Shrugged is 1,100 pages, tiny type, of philosophical mumbo jumbo. The Fountainhead, maybe even Lord of the Rings and Lord of the Flies, these are books you read in your late teens/early 20's (depending on the person) when a young adult is beginning to first develop their unique life philosophy.
Madeline L'Engles series is excellent, very interesting and makes science fun for kids. I'll also add my support for Bellairs. His mild horror books are great, especially back when he wrote them, in that they deal with common problems among kids. The main character is a dorky, overweight book-worm living with his uncle, who deals with the typical problems such an environment causes for a young boy. He also solves many of the problems with quick thinking, and IIRC eventually gets a female friend that is an excellent role model for girls as well.
The Xanth novels are pretty good. Funny, weird, and the main characters display excellent morals. Like Narnia, but not quite as good.
When I was a kid I read some of Bradbury's and Asimovs stuff. Alot of Asimovs stuff in particular has a tone of writing appropriate for children. Bradbury's tone is more adult, but the stories are simple enough for anyone. These books really got me fired up about space and science, if you want your kids to be engineers/scientists load this stuff on their bookshelves.
LeGuins Earthsea books are great but her other stuff I would catergorize with the books at the top, too philosophical for the very young.
You may want to look into the graphic novels Maus I and Maus II. They are about a polish man in america who visits his father and questions him about how they escaped the Nazis. The Jews are all drawn as mice and the Nazi's as cats, it's an excellent way to introduce the subject of WWII to children.
EDIT: Oh, and my GF read some of the Redwall books. I haven't but she says they are good for kids. Since she is an elementary school teacher I find her opinion hard to refute
