While the competition was going on, I came up with my own list of Christmas-adjacent movies that the teams did not mention. They included:
Die Hard II--while not as popular as the first movie (and for good reason), it's still clearly set at Christmas
Lethal Weapon--being set in Los Angeles is one of the reasons that people tend to forget that this favorite buddy-cop movie was set at Christmas
Star Trek Generations--sure, it's just a scene set in the fantasy realm of the Ribbon, but Picard had quite a set of Christmas decorations set up for his imaginary family.
Batman Returns--I recently saw an article that claimed that the Batman/Catwoman relationship makes this one of the best romantic Christmas movies. I will say that the recognition scene at the party is one of my all time favorite movie moments: "Does this mean that we have to start fighting?"
Iron Man 3--again, Christmas doesn't play a huge role, but it is set at Christmas
The Long Kiss Goodnight--this is a personal guilty pleasure with two of my favorite stars working together: Geena Davis and Samuel L. Jackson
Rocky IV--one of my favorite Rocky movies has its fight in Russia on Christmas day
There must be others, but these are the ones that made my list. I don't think that any of them really banked on the role of Christmas in the movies as a draw to theaters, but it's an interesting touch that each of them have added. By the way, although they don't count as movies, I've been pleased the past couple of years with Marvel's new additions to my list of Christmas favorites: The Guardians of the Galaxy Christmas Special and Hawkeye. I highly recommend both of them.