Now that I've watched it a few more times, I've noticed one thing with this movie. The music. Aside from the story and the cinematography and the editing which all are so well done that you feel like you are there with them; the music is a big contributor to the feel of the movie, and in my opinion, more so than in a lot of films.
It is very subtle, it has taken me 10 viewings to even notice there was music there. It really helps create the atmosphere, going from lighthearted, almost fun in the beginning with various rock/pop tracks into deep and moving operatic styles as the story progesses into the war and further.
It is the top of my list of favourites for many reasons, but I think mostly it is the way the whole package comes together to tell the story of what happened that makes it so good.
Well worth viewing many times over.