@tsutohiro: I'm pretty sure Planes, Trains and Automobiles is a Thanksgiving movie. Still, I'd count it as a holiday-season movie for what that's worth.
I may be a bit of a grinch on this, but I don't consider Die Hard, Lethal Weapon, Batman Returns, etc... "Christmas movies", because while they may take place at Christmas time, the holiday itself has nothing to do with the movie's plot. They could have easily taken place during the Forth of July with limited changes. For me, Christmas movies should be about Christmas and all the traditional elements associated with the holiday. I am probably old fashioned but that would include the spirit of giving and "peace on Earth, goodwill toward men." Now, I believe that Die Hard is the second greatest action movie of all time, but I would not describe it as a Christmas movie. Christmas Vacation, A Christmas Story, The Bishop's Wife, Holiday Inn, Bad Santa, Scrooged, Christmas in Connecticut, The Nightmare Before Christmas, Arthur's Christmas, and Elf are examples of movies I would say easily qualify by my personal definition.
Anyway, my favorite is Miracle on 34th Street (1948).