Plenty of other people will tell you about the ridiculous lengths the Kranks' neighbors go to in attempts to emotionally and socially blackmail them into celebrating Christmas "like they ought to," or the headache-inducing panic and breakdowns of Nora at every minor provocation. And they're absolutely right. Although these were intended to contribute to the film's comedy, their sloppy execution instead turns them into key components of what makes this movie so utterly terrible.
What I'd like to highlight, however, is the fact that this film feels like its first and second halves were each ripped from separate films, and then stitched together in a freakish Christmas Flick Frankenstein. After the neighborhood has spent the entire first half of the film tormenting the Kranks, the movie does perhaps the most abrupt about-face I've ever seen, suddenly making an attempt to lead up to a "heartwarming" ending that is so entirely unearned that it slips on the ice and falls on its face in the process. It's legitimately tough to believe, even on a first-viewing, that the first and second halves are the same movie.
Now, if you want a "dumb, mindless fun" flick for Christmas, and the idea of immense social pressure being inflicted on a family for simply deciding not to celebrate an extremely mainstream holiday sounds hilarious rather than extremely uncomfortable, then by all means, this is the film for you! Otherwise, however, stay FAR away, this film isn't worth your time.