I've read Goethe's "Faust" and liked it very much. I've also read some Schiller.
I enjoyed Hesse's "Steppewolf", "Narciss and Goldmund" and "Siddhartha".
From Mann brothers unfortunately I've read only Henri Mann's dilogy about Henry IV.
If you consider Kafka german(he was german speaking) then I've read some of his short stories.
Not sure about Zweig either. I think he was Austrian, wasn't he? I love "Impatience of the heart"- one of my favorite novel overall.
The same thing about Meyrink- he was probably austrian. I like "Golem" and "Angel of the West window"
My favorite German writer is probaly Leon Feihtvanger. I've read a lot of his novels: "Spanish ballad", "The Opperman family", "Success" and many others.
Another german author is patrick Suskind. His "Perfumer" is outstanding

