The Boy in the Striped Pajamas, I cried. The Divide made me want to cry, but I found the content distracted me a bit. It left me with more of a disturbed feeling.
Grave of the Fireflies, the first time you watch it, it's kinda sad. Then the second time you watch it, you'll cry when you watch the beginning again. Also Gladiator was pretty sad and Das Boot too.