1) It's A Wonderful Life (1946)

A movie which is nothing short of iconic, and one which would take something seriously special to shift it from the top spot. James Stewart stars as a suicidal man about to jump to his death, before a mysterious guardian angel takes him on a journey which shows him that his existence has been far from futile all along. The very definition of a 'feel good' film, It's A Wonderful Life is a solid gold holiday classic.