One film brought a tear, but I was 13 years old. The bit at the end of Schindler's List where he's saved the people and he's about to drive off to escape the Russians. Schindler breaks down, saying that he could have saved a couple more if he'd sold his watch (or other personal valuables), and his 'saved' tell him he did all he could. Before that, I don't think you have time to really contemplate each atrocity before the next one comes along. Somehow, that final scene brings it all to a head.