Amelie is a good French film. Are you only interested in French or German? If not, you might enjoy a trio of Polish filmes by Krzysztof Kieślowski called Three Colours (Red, White and Blue).
La Vie En Rose was a movie about the life (or parts of it) of Edith Piaf. Heartbreaking! It is French.
M is a movie about a child molester being pursued by the criminals of the city. It is German.
Diabolique is a french movie about two women trying to kill one’s husband, and the other’s lover.
Das Boot. Get the Director’s Cut. Seriously, one of the best movies I’ve seen in a long time.
Aguirre, The Wrath of God.
Herzog’s remake of Nosferatu.
If you’re into silent films, then definitely watch Das Cabinet des Dr. Caligari, Nosferatu, Metropolis, Der Golem, and The Last Laugh.
And finally, Triumph of the Will. I am not a Nazi sympathizer, but it is definitely a revolutionary and influential film.