It's a very strange sort of book. All of Gaiman's work is strange.
My bookseller mentioned to me that a lot of her buyers were adults, who liked it more than their children–Coraline is a YA novel.
I can see why. It's got a somehow adult feel to it, without Coraline sounding too old for her age.
I can't say I'd recommend it as a YA novel, but it's a pretty good read if you're an adult.
And no, I've yet to decide whether I like Gaiman.