I've read numerous books about the history of the Third Reich, including two of Richard Evans' trilogy. "The Rise and Fall of the Third Reich" is also good (surprisingly so, since it was written for the mass market).
However, this book, a novelization of the life of Hermann Goring, gave me something that history books can't give you - a comprehensive and more personal study of what you could call "evil" (or perhaps there's some psychiatric syndrome that can be applied here).
Leffland takes us from Goring's childhood to his suicide a few hours before his execution in Nuremberg. The novel is rich in minor and major characters, the details of whose lives give the reader a terrific understanding of daily, even hourly life in the Third Reich. And, the details of Goring's life are stunning and chilling. His looted art collection, his enjoyment of French pate fois gras when the bakeries in the cities were empty, his bizarre collection of outfits, the details of his many houses. All of these details are set against such events as the Rohm purge, the passage of the Nuremburg laws, his conduct after Kristallnacht (he proposed that the Jews pay a billion marks penalty for causing Kristallnacht), etc., etc., etc.
The picture of the war and the delusion that fueled it and continued to keep it going, even as it came down to the end - fighting it street by street in Berlin - is terrific.
I highly recommend this, not only for people interested in the Third Reich, but also for people who like a good, long read. At 950 pages, it's satisfyingly long. I awoke every day eager to read more.