Whitey's voice. While most liken it to nails on a chalkboard, others are more forgiving because Whitey is just such a Nice Guy.
The animation. Nobody will deny that this is a very well-animated film, especially since it was one of the last major American hand-drawn animated films, but there's some debate whether it's dissonance from the vulgar humor makes it funnier or just awkward.
Broken Aesop: As the Butt Monkey, Whitey was intentionally written to be as freaky as possible. So it comes off as hypocritical for the final lesson of the movie to involve Davey shaming the town and the audience by proxy for treating him as such
Darkness-Induced Audience Apathy: Davey is so unabashedly awful throughout the film that the only possible way to make him seem sympathetic is to make the townspeople ever worse to Whitey.
Ear Worm: Even people who don't like this movie (or Adam Sandler in general) have admitted that the songs are pretty catchy.
Ensemble Darkhorse: Eleanor for being as nice as Whitey while also having a slightly less obnoxious voice. Not to mention she can kick your ass if she needs to.
Amongst the writers, Mrs. Selman ("...with the one extra breast"). Apparently, they thought it was so funny that they gave her some more scenes.
Guilty Pleasure: For some. Mostly because the pickings are pretty slim when it comes to movies that are even remotely Hanukkah-themed. The animation helps.
One of the biggest criticisms for this movie was how Davey does not deal with his loss the way most people really do, and rather than be introverted and antisocial is a troublemaker. Years later, Adam Sandler would star in Reign Over Me, one of his few dramatic roles where he was hugely praised for his sincere portrayal of someone who lost their whole family to a tragedy.
Jerkass Woobie: Davey, after you learn that his parents died when he was a boy. On Hanukkah, when they were on their way to watch his basketball game. Which, before he learned of their deaths, he worked himself to the core winning as a tribute to not only his parents, but to the parents who always came to watch their kids play basketball... despite the fact that they never win. Hoo-boy
Non-Indicative Name: Despite having a few references to Hanukkah, the film has little to do with the eight nights of Hanukkah and is more of a buddy comedy (and the year the film was released, Hanukkah began four weeks before Christmas).
What Do You Mean, It's Not for Kids?: Yes, it's an animated wacky holiday musical rife with toilet humor, but it is most definitely not for children, what with the focus on deer shitting lots of poop. Doesn't help that in Canada, the movie's rated PG. 14A would have been more like it.
The Woobie: Whitey. Whether you like him or not, it is sad to feel like you don't exist by having someone you've been trying to make into a better person tell you so.