The Secret of NIMH
Imaginative, unafraid to shy away from violence and dark themes, brilliant use of imagery and sound to evoke emotional responses. Just a great movie.
I was actually afraid of it when I was a kid, I only grew to appreciate its tense atmosphere as I got older.
Also mad props for the main character being just a normal single mom trying to do whatever she has to for her kids despite being horrified by the shit she sees and does.