Without wishing to make this thread appear repetitive, I'd have to say:
Die Hard
Miracle on 34th Street (remake)
Bad Santa
Elf
Scrooge (Alistair Sim version, but not the horrible colorized version channel five show)
a few more obscure / less obvious ones:
A Midnight Clear (virtually unknown movie set at the tail-end of WW2)
Trading Places
Edward ScissorhanRAB (well, it is set around Christmas and has snow!)
From a bah humbug point-of-view, how about most hated christmas film list? My top three would be:
Santa Claus The Movie
Love Actually
Nativity