This is a nice list of “lost” (read: not quite obvious) literary classics that—in the wonderful age of the digital reading device—anyone can read for free. I’d especially recommend the Montaigne:
Forgive my one concession to the obvious, but Montaigne’s essays are weirdly optimized for modern life (easy to read on a phone, for one thing), not to mention just weirdly modern, and way too wonderful to overlook. Sample titles: “Of Age,” “Of Drunkenness,” “Of Coaches,” “Of Cannibals,” “Of Liars,” “Of Vanity,” “Of Sleep.”
Or you could pick up the Penguin Classics edition, which I have quite enjoyed.