One of Tyler Cowen's readers asks which books are the Great Gatsby of each decade since the 20s? I take this to mean books that both sold well and have come to represent their era. Sounds like fun. Here are Tyler's picks in bold, with alternates from me:
1930s: The Grapes of Wrath, John Steinbeck. That would be my choice too, though I might add Gone With the Wind as the biggest escapist novel of a decade that really needed its escapism.
1940s: Farewell, My Lovely, by Raymond Chandler. This is a tough decade. How about The Naked and the Dead instead? — though it's true that it doesn't really represent the 40s as they were lived in America.
1950s: Invisible Man, by Ralph Ellison, with Kerouac’s On the Road as a runner-up. Both good choices. The Man in the Gray Flannel Suit too, though it doesn't hold up well. And how about On the Beach?
1960s: Catch-22, by Joseph Heller, with The Bell Jar and Herzog as runners-up. Hmmm. Tough decade. Valley of the Dolls? Portnoy's Complaint?
1970s: This is tough. There is Vonnegut’s Breakfast of Champions, Stephen King, and even Peter Benchley’s Jaws. I’ll opt for Benchley as a dark horse pick, note that these aren’t my favorites but rather they must be culturally central. Jonathan Livingston Seagull is another option, as this truly is an era of popular literature. I'd choose The Serial, though I don't think it was ever a bestseller. Or maybe The World According to Garp or Zen and the Art of Motorcycle Maintencance.
1980s: Tom Wolfe, The Bonfire of the Vanities. Good choice. The Hunt for Red October belongs here too.
1990s: The Firm, by John Grisham, or Barbara Kingsolver, The Poisonwood Bible. Maybe Brokeback Mountain. Perhaps I'm being too hard on the 90s, but I'd pick The Bridges of Madison County. Also, Primary Colors, though that might be my political bent talking.
2000s: Malcolm Gladwell, The Tipping Point. Oh come on. Let's stick with fiction. Maybe the Harry Potter series? When I think of the aughts I think of terrorism and economic collapse, but I'm not sure there were any big novels that really captured either of those things.
UPDATE: One thing that occurred to me while I was writing this, and also occurred to a few commenters, is that sometimes books written in one decade are good representations of another decade. Among WWII novels, for example, I'd say that The Caine Mutiny is more iconic of the 40s than The Naked and the Dead. But Caine was written in the 50s.
But maybe that doesn't matter. Who cares when a novel was written? Maybe Caine Mutiny is iconic of the 40s and Lord of the Rings is iconic of the 60s, even if they were written in the wrong decades.