Read half of page 2, so i'm grunching and don't know if anyone else has mentioned it but...
Lion King. When Mufasa gets trampled & Simba comes down and says "Dad? Dad. Come on. You gotta get up. We, we gotta go home." it's heartbreaking.
I watch it with my kids now & it makes me cry a bit harder.
also, to keep it along cartoon movie lines, Mars Needs Moms: I'll spoiler it cause I know you all LOVE your cartoon movies.