Each character in Nightmare, to me, is very lovable. There are all bizarre in their own ways, but even villians like Oogie Boogie and Dr. Finklestein are extremely intriguing characters. Werewolves, vampires, and two-faced politicians... you can't help but love it!
Jack is, of course, very interesting and, after seeing the movie my whole life, I've only just begun to understand his amazing character arc over the past few years. In the beginning of the film, Jack goes through a time of doubt and seeks change. After he finds Christmastown and decides to take the holiday over and fails, he realizes that all he needed was right there in his own town, for he IS the Pumpkin King! Being a young adult myself, I've learned that sometimes life throws curve balls your way and you lose a sense of yourself or forget who you are for a short period of time. I don't know about you haunters out there, but sometimes when I go through a tough time or a moment of doubt, no matter what it it may be that is going on in my life, luckily, I always come around and remember who I am and must remind myself that I too, AM the Pumpkin King (or at least one of the many haunters out there who blog and decorate). Overall, you know a film is great when you can keep watching it your whole life and continue to learn more from it, especially when you feel you can relate to a well-told story with a strong character arc.
Another great element to this film besides the amazing animation, design, and story, is the music. There's just nothing else like a Danny Elfman soundtrack. Elaborate and intricate for sure, yet playful, curious, and exciting. Elfman's music isn't ever just ambient; his music plays a role of its own in whatever films its featured in, particularly Tim Burton's movies and Nightmare is no exception. Songs like "Making Christmas" and "Oogie Boogie's Song" are just two of the many examples of fascinating composition.