Hmmm.... I hope this isn't for kids! :-) Neil Gaiman wrote a pretty freaky story here and I would be scared for ages if I'd read this as a child! :-)
Reading Coraline was like reading a Tim Burton film. If you see what I mean. The one that readily comes to mind is The Corpse Bride, I guess that's how I imagined the characters.
Coraline is the child in the center of this story - she goes through a door she's not supposed to go through in her new house and ends up in a parallel world where someone really, really wants her to stay. It's a twist on the Alice stories, but spooky rather than silly.
I suppose what makes Coraline good (as well as scary) is how normal the strangeness is. There are no fantastic creatures or monsters, it's all bizarre but in a natural way. That makes no sense when I re-read it, but I can't think of a way to explain it better.
I guess you should just read it yourself and see!
Challenges: 999 Challenge, Dewey's Books, Once Upon a Time III