Greatest American Novel project

A couple months back I mentioned a poll regarding the greatest American novel. Since then I've read a few of them and am planning on tackling the rest over the next few years. Here's the list:

• Hawthorne, The Scarlet Letter
• Stowe, Uncle Tom's Cabin
• James, Portrait of a Lady
• Cather, My Antonia
• Wharton, The Age of Innocence
• Fitzgerald, The Great Gatsby
• Hemingway, A Farewell to Arms
• Faulkner, The Sound and the Fury
• Warren, All the King's Men
• Bellow, The Adventures of Augie March
• Ellison, Invisible Man
• Chandler, The Long Goodbye
• Bradbury, Fahrenheit 451
• Updike, Rabbit, Run
• Barth, The Sot-Weed Factor
• Heller, Catch-22
• Lee, To Kill A Mockingbird
• Nabokov, Pale Fire
• Roth, The Great American Novel
• Melville, Moby-Dick
• Twain, Huckleberry Finn

And I want to add a couple of others.

• Steinbeck, Grapes of Wrath
• Mailer, Of a Fire on the Moon

Which makes 23. Any other suggestions? And is anyone else interested in joining in? I can give a few weeks heads up about which book is next if you'd like. What think?