I know it's actually a Thanksgiving film but I always think of Planes, Trains & Automobiles as a Christmas film. I'd also go for Trading Places.
Just watched ending of that and yes i ahd a smile on my face at end. Went to see Nativety 2 last week with mrs and little'un and it was brilliant. Definately worth going to see.
Re: Scrooge, with Alastair Sim I'm with BigLil for these films, and as a Bailey myself, my favourite is It's a Wonderful Life with a special performance of James Stewart as "George Bailey". I also appreciate the 1947 version of Miracle on 34th Street with Edmund Gwenn and a young Natalie Wood. I also enjoy the musical version of Scrooge with Albert Finney.
National lampoon with Chevy chase. Who I suspect looking at the frontage has moved into the house next to us.
Not exactly a Christmas film, but Labyrinth used to get shown every year and it is class, one of Jim Henson's most under-rated works. I also think that Love Actually transcends the cheese and is a brilliant piece of throwaway cinema.
Scrooge - Alistair Sim version and got to be in black and white, not the colourised version Bad Santa Joyeaux Noel