In Woody Allen's 1975 short story "The Whores of Mensa," busty female intellectuals entertain "clients" with verbal diatribes on Melville, Kant and Dante. As the narrator describes it, "nervous girls with black-rimmed glasses and blunt-cut hair lolled around on sofas, reading Penguin Classics provocatively."

Three decades later, Penguin Classics remains one of the few publisher-driven brands that general consumers recognize. But while the name still conjures literary merit and intellectual excellence, the classics business has gotten a lot more competitive since the house launched the brand in 1946. With Barnes & Noble selling its own line of classics and public-domain works widely available on the Internet, Penguin is working harder than ever to keep its versions of the classics on readers' minds.

As it celebrates the 60th anniversary of the line, Penguin is putting tremendous effort into making these titles as relevant and widely appealing as possible. Those efforts include a partnership with Amazon through which the e-tail giant will host an online book club, the Penguin Classics Reading Group, featuring moderated discussions of titles in the Classics line.

The house has also been redesigning the look of its titles, launching a number of variations on its, well, classic-looking books. The Graphic Classics feature cover art by comics artists like Chris Ware and Roz Chast. The Black Classics—named for their uniform black spines and cover backgrounds—account for the majority of the house's titles in the overall line; they represent "the publishing core" of the program, as executive editor Elda Rotor put it. Then there's the Deluxe Classics, featuring more high-end design elements like French flaps and rough fronts (the Graphics line has them, too), and "literary and educational extras." The Deluxe Classics edition of The Odyssey, translated by Robert Fagles, for example, offers an introduction by Bernard Knox (director of Harvard's Center for Hellenic Studies) and a guide for further reading.

Penguin has a lot at stake in keeping the Penguin Classics brand healthy. With its 1,300 titles, the line remains "a big and high-profile part of our list," said Penguin Books president and publisher Kathryn Court. But it's not just about packaging. Court said the future of the brand rests in maintaining excellence, seeking the newest and best translations and finding authors and books to add to the line. Court said defining a Classic is less about the age of a title than its importance and expected longevity. "We don't have a date cutoff, but we do want to feel the book has already stood the test of time.... It's really about books we believe will be around 50 years from now."

The Bestselling Penguin Classics

All Time 2006
Source: Penguin
1. The Canterbury Tales 1. The Crucible
2. The Grapes of Wrath 2. The Odyssey
3. The Epic of Gilgamesh 3. The Grapes of Wrath
4. Anna Karenina 4. Death of a Salesman
5. The Three Theban Plays 5. On the Road