This film is one of my daughter's favorite films, as well as one of my own. I definitely recommend it for parents who have older children, but younger children JUST MAY be frightened. You know your child better than I do, though, so use your judgement. It is done with a very dark version of the animated puppets that are used for many of the old Christmas films (Frosty the Snowman, Rudolph the Red Nosed Raindeer, Jack Frost) that many of us grew up watching.
Spoilers contained, so go out, watch the movie before you read this entire node.
Jack Skellington, king of Halloweentown, is bored of Halloween. He feels that there's something missing from his life, so he wanders around until he discovers Christmas Town. He gets the idea to put on Christmas himself, to give Santa Claus a break. But, his lack of experience, along with his helpers, lend to a very different type of Christmas.
In the meantime, Sally, laments that she cannot get him to notice her. In the end, he discovers the girl, sets things right with Christmas, and has his enthusiasm for Halloween reinvigorated.
Directed and characters by Tim Burton, music (a very big part of the film) was by Danny Elfman (as well as a few voices). (Paul Reubens plays one of the characters in the film as well!)
IMDB recommends that you also see Halloweentown, which is another light-hearted kids movie about a town where every day is Halloween. Coincidentally, it's another of my daughter's favorite movies. If you have the Disney Channel you can see it about thirty times next Halloween.