My all time favorite actual Christmas movie is "National Lampoon's Christmas Vacation".........physical/slapstick comedy usually doesn't do it for me, but this film is so full of family dysfunction, unfulfilled expectations, and surprising tenderness that it overcomes the stupidity. (And even I've gotta admit that seeing Clark Griswold staple his sleeve to the roof is funny as hell---I don't know HOW many times I've done the same sort of thing tacking up lights around my own house
I especially love the diatribe Clark goes into near the end of the film when he receives his Christmas 'bonus', which ends with "HALLELUJAH! Holy s***, where's the Tylenol?"
One film they show at Christmastime, but isn't really a Christmas movie, is "The Sound of Music", which is near the top of my all-time favorites list. It was on ABC last night, and even after 40 years, it still moves and delights me in ways no other movie ever has. I still mist up every time the Mother Abbess sings "Climb Ev'ry Mountain", giggle like a child at the marionette show put on by the von Trapp children as they sing "The Lonely Goatherd", and thrill to the booming organs at the beginning of the cathedral wedding scene.