The Nightmare Before Christmas (stop motion)
Blu-Ray/DVD site; Halloweentown (fansite); IMDb; Rotten Tomatoes; 3-D theatrical site; Wikipedia

I don't really know what to say to adequately express how great this movie is. Let's see... it's about Jack Skellington, aka the Pumpkin King, who is from Halloweentown. All sorts of weird things live there, and go out into the world once a year, on Halloween, to spread fear. They enjoy this greatly, and Jack is the best at it. However, lately he just isn't feeling it, and wants to find something new.

Then he and his red-nosed ghost dog, Zero, are out for a walk in the forest, and discover there are trees which serve as gateways to every holiday. He stumbles into Christmastown, and loves it. He returns home and tries to explain it to everyone, but they don't understand it, since their perceptions of everything in life are based entirely around Halloween. Jack himself doesn't truly understand it, but he desperately wants to. So he foolishly sends three miscreant trick-or-treaters (Lock, Shock, and Barrel) to kidnap Santa Claus so that he and his friends can take over Christmas for the year, Jack dressed as Santa, delivering presents to all the children of the world....

There are all sorts of problems with this. One is that Lock, Shock, and Barrel work for Oogie Boogie, aka the Boogieman, who is just this terrible troublemaker completely at odds with Jack. Why Jack trusted Oogie's proteges to handle this task and heed his warning not to involve Oogie is a bit perplexing, but hey... it serves the story. Of course they turn Santa over to their master after kidnapping him.

There's all kinds of other stuff going on, too. There's a mad scientist who created a living, life-size rag doll named Sally, who's secretly in love with Jack, and who has a vision of his attempt to handle Christmas going horribly awry. Jack pays no heed to her warnings, of course. The citizens of Halloweentown, of course, make some terrible presents, which scare all the children they're delivered to, and the human authorities end up shooting down Jack's sleigh; he then returns to Halloweentown and discovers Oogie torturing Santa Claus, as well as Sally, who tried to rescue him, so Jack and Oogie have a confrontation.

Not sure what else to say without spoiling anything too much (which hopefully I haven't done yet). But the songs are all really great. The characters are great. You can of course watch the movie at Halloween or Christmas (or any time of year), but while it seems more Halloweenish, it's really mostly a Christmas movie. Just cooler and darker, while just as emotionally moving as any Christmas movie, without being sappy.