Another vote for Bad Santa. This is the last movie I can remember seeing which had people laughing so hard that they were literally crying. It’s also got more honest “Christmas Spirit” to it than most sappy generic holiday movies.
For those who haven’t seen it, do so. Note that it’s got an R rating for language. Few movies in recent memory have been so gloriously foul-mouthed, as the quotes people have posted show. When it was released there were some stories of clueless parents bringing little kids to it, assuming it was something innocent, and then fleeing the theatre in shock after the opening monologue.