While most movies which make us cry at a character's death usually do so after spending the entirity of the film establishing the character before killing them off, Up pulled off this miraculously within the first ten minutes.
The opening montage of Up ranks among the best loved sequences in the history of animation; it's a real masterclass in establishing characters, their relationship and the passage of time as effectively as possible. From the struggles of owning a house to the realisation that they can't be parents (how many other kids' films deal with the concept of a miscarriage?), Carl and Ellie Fredrickson's joys and woes are condensed into one perfect, wordless sequence.
Ellie's death brings this smorgasbord of life's trials and tribulations to an end, and it feels as if we know her as well as Carl himself. Perhaps no other film - animated or otherwise - has so perfectly distilled the feelings of love, life and loss in such a short space of time.