For pop non-fiction / pop-history:
One Summer, America 1927. The quintessential Bill Bryson non-fiction novel. If you've never read Bryson (A Walk in the Woods, A Short History of Nearly Everything), then you owe it to yourself to start here. One of my favorite non-fiction books.
Flash Boys. A Michael Lewis financial pop-history book about the Flash Crash. Classic Michael Lewis (The Big Short, Moneyball, etc) style.
Devil in the White City, a story of the Chicago World's Fair and the first serial killer (I believe this is being made into a movie soon)
The Smartest Guys in the Room, the Rise and Fall of Enron
Bad Blood, the story of Theranos and Elizabeth Holmes. Basically, if you're wondering why Netflix, CBS, movies, etc., have all made Elizabeth HOlmes / Theranos shows/docs recently, it's because of this book
I'd also recommend 'Under the Banner of Heaven,' about the rise of American Mormonism, and 'Going Clear' about Scientology. A lot of my 'pop history' non-fiction books fall into certain categories ... Financial scandals, corporate scandals, or weird times in history that define eras larger than they are. Others include 1946: The Making of the Modern World, the War that Forged a Nation: Why the Civil War Still Matters, every Bill Bryson book, most Michael Lewis books, Red Notice by BIll Browder, Winter is Coming by Garry Kasparov (both books about modern Russia), Havana Nocturne about the mob & Cuban revolution.