“Stories you read when you’re the right age never quite leave you. You may forget who wrote them or what the story was called. Sometimes you’ll forget precisely what happened, but if a story touches you it will stay with you, haunting the places in your mind that you rarely ever visit.”
–Neil Gaiman, in the introduction to M Is For Magic, which, contrary to its title and designation, is not really appropriate for children
Gaiman has written multiple novels for children and for adults, as well comic books. Some of his best known books are Stardust, American Gods and Coraline. I particularly recommend The Graveyard Book.