Sometimes humorous. Sometimes serious. Always nonfiction.
The Botany of Desire: A Plant's Eye View of the World  by Michael Pollan.
The Guns of August  by Barbara Wertheim Tuchman.
October 1964  by David Halberstam.
A History of the World in 6 Glasses  by Tom Standage.
The Ghost Map: The Story of London's Most Terrifying Epidemic and How It Changed Science, Cities, and the Modern World  by Steven Johnson.