So, nonfiction/historical works
Given the magnitude of the event, it's pretty embarrassing how little the average American knows about
The Rise and Fall of the Third Reich; if that sounds like you, read the book. Yes, it's long, but totally worth it.
Speaking of WWII, war crimes. I won't recommend a Holocaust book, because who doesn't know about the Holocaust, but if you're not familiar with
The Rape of Nanking, one of the truly dark moments in Japanese history (and one which they refuse to apologize for), you really should be.
Keeping with the general theme of awful stuff happening, I think I got out of high school without ever spending a single day on African history. That's embarrassing. If you're in the same boat, read
The Scramble for Africa.
But that was all so long ago! There's stuff going on this
very moment that could be ruining your day! In order not to be stuck in the past, you should read
The New Jim Crow.
On the same general topic, you should read
Seeing White: An Introduction to White Privilege and Race Also, everyone should read
Shake Hands With the Devil, about the Rwanda genocide.
"But BadDecissions," you say, "do you have any book recommendations that won't leave me feeling worse then I did before I started reading?" Well of course I do! There's ... uh ... well, you could read ... uh ... look, I'm not actually a manic depressive, it's just that my non-fiction section is a little bleak. If you're willing to go outside of "horror and historical," then you, and everyone else, should read Wodehouse. Starting with ... hm ...
Life At Blandings, which is apparently also called The World of Blandings. edit: I almost forgot
The Fatal Shore, on Australia! How could I!