So, German sci-fi? Metropolis, but that's a film. Anything more and I'm struggling. Kurt Vonnegut? He bummed about in Dresden for a bit, but he was American. Von Daniken? Swiss, and he thinks it's all true.
Luckily we've got Andreas Eschbach. Only one book in English though, but it is a great one.
It starts in the desert, describing a society dedicated to the making of carpets for the Emperor's Palace. They're made from the hair of the makers' wives and daughters, and each one takes a lifetime to complete. The only clue that it's science fiction at the beginning is the rusted and useless rayguns carried by the merchant's guards.
I'm not going to give much else away, because the plot unravels really nicely - each chapter's like a short story focusing on one character, but all the pieces fit together. The sense of scale, both in time and space, is immense and it's contrasted with the second by second ritual of tying these carpets together.
There's also friction between the cynical and gloomy worldview about politics, power and faith, and the role that love plays in changing the rules.
A big recommendation from me - beautiful and poetic with big ideas about science fiction and human nature.