Disney's Merlin. When Arthur was a squirrel and this female squirrel liked him. Then he turns back into a human, breaking the squirrels heart.
It got me every time when I was a kid.
2 days ago I saw The Godfather. At one point, there's this gorgeous shot of the family house, all yellow rock and green plants. It was so beautiful, I got tears in my eyes. Not sure why, maybe it triggered some inconcious sad memory.