First of all, fuck Grave of the Fireflies, wasn't that older brother sitting on crazy cash the entire time and didn't do shit with it? For mine, Schindler's List ending, all the things he could've sold to save more lives. I have never seen regret and sorrow better acted out in my life:
Two that came to mind that haven't been posted yet.
I'm a sucker for powerful music behind the sadness and the end of Moulin Rouge has made me cry a few times.
Scene in Star Wars Episode 3 where Obi-wan is yelling at Anakin. His heart-broken rage is just amazing acting.
Basically, Ewan McGregor is the fucking man at powerful emotion.
Can't find a good clip of it, but Where the Red Fern Grows. The scene where Old Dan dies and then Little Ann dies of loneliness. I'm a dog lover and we watched the movie when I was a kid in school and it's always stuck in my mind.
The only movie moment that has ever made me tear up was at the end of "Life is Beautiful" when the kid sees the tank and runs towards his mom yelling "We won! We won!"
Couldn't find the actual ending on youtube but this is pretty close. As dog lover with 3 dogs....I can't make it through this without tearing up. Every damn time.
I've had so many dogs in my life and this movie reminded me of a black lab we had for over 17 years who was put to. It has been the only movie where I actually teared up and cried . ;\