"Children Of Men"
It is based on a book by P.D. James (which I haven't yet read) and gives an alternative take on the Nativity story. The world has gone to pot, social upheaval on a dramatic scale, masses of immigrants/refugees from all over the world coming to Britain. No child has been born in the world for 18 years. Then, a young black woman is discovered to be with child. The climactic sequence towards the end is incredibly powerful and very moving.
The film is full of sly references to its biblical template for those who wish to see them (but less obviously than in the book apparently). I think it would be great for use with 6th form R.E. students as an alternative way into the Nativity story, but also to reflect on Messianic expectation amongst the Jews of Jesus' day and how this was then reflected in attitudes to Jesus.
I've already started using it in Film Studies, the excuse being the excellent cinematography during the aforementioned climactic sequence, much of which is filmed without a break (woman carrying baby with male protector, trying to make it through the war zone that is Bexhill-on-Sea! :-). Nice cameo from Michael Caine... phrase "gone to pot" quite appropriate in his case!