If you want interesting films, where the film-makers tackle both contemporary issues and the censors, then you really need to look to East German cinema. West German films tend towards showing lots of happy peasants working hard for their kind, generous bosses, and month by month churning out more tractors than ever before. Even though as kids growing up in the West we were always told it was the other way round.
The works of director Kurt Maetzig is a good place to start (although even he in later life was embarrassed by the hagiographic Ernst Thälmann films). Vergeßt mir meine Traudel nicht and
Das Kaninchen bin ich may surprise you (The latter was banned shortly after its release, and I can't think of a single West German film coming close to such a fate). You've possibly seen Der schweigende Stern in it's bastardised MST3K version as First Spaceship on Venus but don't let that put you off. If you want more then
here's a very good blog that gives the films a fair assessment on their own merits without getting bogged down in the politics.
The Sissi films however are just the most expensive pieces of fluff in two decades of film-making on a theme of don't-mention-the-war.