I don't know if its a Christmas movie but I think it is.. It at least has a scene about Christmas and its one of my favorite movies of all time.
The animated classic set with the Land of Forgotten Toys, Santa, Rudolph and Frosty of course
Polar Express is near and dear to me..
Other great ones we enjoy are the original animated The Grinch that Stole Christmas (or the Jim Carrey one), Jim Carrey Christmas Carol, Santa Clause, Miracle on 34th Street, Charlie Brown Christmas, Mickey's Christmas Carol, and my kids and my husband are particularly fans of Elf and Muppets Christmas Carol.
What are your favorites?