Maybe a boring and obvious choice but It’s a Wonderful Life is the one movie I can’t go without every Christmas. It went into wide release in January of 1947 so probably wasn’t even originally marketed as a Christmas movie (but if they did try and sell a Christmas movie in January that would explain its poor performance at the box office). In fact, only the last half of the film takes place at Christmas. Every year I feel tempted to even skip the first hour and a quarter and just jump to Christmas Eve and every year I’m glad I didn’t. You really need to watch George Bailey’s life of watching his dreams slip away to feel the full impact of his Christmas Eve realization that he had been living a wonderful life without fully realizing it. Every year it makes me cry and every year it makes me thankful.