For history nerds:
Really enjoyed A World Undone: The Story of the Great War, 1914-1918 by G.J. Meyer.
Extremely accessible history of WWI with a good look at the mentality that led to it and the evolution of the understanding of the modern world. Each chapter ends with a little pseudo-chapter going in depth about an interesting subplot tangentially related to the chapter before it (covering the history of Cossacks after a chapter about America rolling towards war, drawing a parallel between the Cossack homelands and the American West, for example).
Currently reading Spain in Our Hearts: Americans in the Spanish Civil War, 1936-1939 by Adam Hochschild. More reading this on the back of the brilliance of Hochschild's history of the Belgian Congo (King Leopold's Ghost) than any particular interest in the Spanish Civil War, but hey - totally unexplored history for me too, so it's got that going for it.