Joyeux Noel is a foreign film (filmed in at least three languages - English, French and German) based on the true story of the Christmas Eve Truce of 1914. This is not a children's movie at all, but I thought I'd share it here as it has some incredibly beautiful scenes which could be shared with your family at Christmas.
World War I was a brutal war and the movie rightly gives some of this context which gives more meaning to the truce. We are introduced to a Scottish priest and two brothers who all serve on the front lines, to a French lieutenant who hasn't heard from his pregnant wife - behind enemy lines - for months, to a German officer and to a German soldier and his Danish wife (who are both opera singers) and other interesting, minor characters on each side who come together, partly through the gifts of song and of faith, on Christmas Eve and Christmas Day and celebrate and bury their dead together.
The film is beautifully made and very moving, but there are many elements that are inappropriate for children - particularly the violence of battle scenes, a brief bedroom scene and a rather disturbing interaction between an emotionally broken young man and his dead brother.
One of the most beautiful and understated scenes I've ever seen in a movie is contained in the opening scene. After a brief introduction giving a sense of the indoctrination of hatred stirred up in the days leading up to the war (particularly in the schools), we find the news of war traveling all the way to rural areas of Scotland. The scene moves to a Church where a priest is lighting candles and and a young man is working on painting a statue. His older brother storms in to ring the Church bells, ecstatic that "something's finally going to happen around here" because they're going to leave for war. The brothers leave and the wind from the door snuffs out the candles. We're left with only an expression on the priest's face that says everything. (To me, he seems to say: "Father, forgive them, for they know not what they do.")
Lots of great material for discussion here (particularly for teens) including the political reality of the priest's military superior (presumably an Anglican bishop) who, quite naturally, tows the line of his superiors.
From what I've read about the real-life Christmas truce, the filmmakers went to great lengths to portray it accurately (if at times representatively) and I was impressed with how much acknowledgement this non-believing director (from what I've listened to of the commentary so far) is willing to give to the Faith in general and to the priest in particular, who clearly sees all of the men from both sides of the trenches as belonging to his flock.
Although this is a war movie with a great Christmas theme and certainly one with political elements, it points higher to practical and spiritual realities of hope, love, forgiveness and brotherhood.
So, I suggest that you watch this first and then decide what portions of it you might like to share with your children. By the way, when this movie first came out, it was given an "R" rating, but, after huge objections from major critics, was updated to a "PG-13" rating. I can see where it sort of straddles that line.
UPDATE: Silly me. I forgot that it also includes the Latin language (but I don't want to say more as I don't want to spoil some of the very beautiful parts before you see it).
You can view some music and clips online here.