I mostly read non-fiction, as I have an ongoing project based on a diary I discovered (on Ebay's Ephemera Section) written by a young German woman living in Hamburg in the 1930s. It covers the Nazi years.
For the wider context, I have read 'Gone to Ground' by Marie Jalowicz Simon, a Jewish woman who lost both parents by the age of 19, but managed to survive by hiding in Berlin. It is harrowing, exciting, and very percipient. She leaves out nothing about the darker side of human nature, but also about the side that (just about) makes life worth living. She is very intelligent and judgmental, though her memoir, written in later years, mellows somewhat her memory of her earlier judgmentalism. She survived to become a university lecturer in Classics. It is a book I plan to re-read, as she was aware of many complexities, compromises and nuances even at age 19.