Do comics count as well as source? If so, the my favourite movies would be the Batman Dark Knight Trilogy. If not, the good ol' Lord of the Rings would be my choice.
Edit:
Oh, maybe a more serious choice:
Umberto Eco - The Name of the Rose
recently i watched a great movie called 'arrival' starring amy adams directed by denis villeneuve, based on a short novella 'story of your life' by ted chiang