Used books are the backbone of AbeBooks, and it's always interesting to see the diversity of books that are being sought after and bought on the site. Here are the top 50 used books purchased on AbeBooks this year.

[More from the AbeBooks Year in Review]

1. The Da Vinci Code

Dan Brown
First Published in 2003

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2. In Cold Blood

Truman Capote
First Published in 1965

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3. Tuesdays with Morrie

Mitch Albom
First Published in 1997

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4. The South Beach Diet

Arthur Agatson
First Published in 2003

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5. Freakonomics

Steven Levitt
First Published in 2005

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6. The World is Flat

Thomas Friedman
First Published in 2005; Updated in 2006

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7. Who Moved My Cheese?

Spencer Johnson
First Published in 1998

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8. The Seven Habits of Highly Effective People

Stephen Covey
First Published in 1989

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9. To Kill a Mockingbird

Harper Lee
First Published in 1960

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10. The Kite Runner

Khaled Hosseini
Published in 2003

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The Purpose-Driven Life

  1. The Purpose-Driven Life, Rick Warren
  2. How Opal Mehta Got Kissed, Got Wild and Got a Life, Kaavya Viswanathan
  3. Five People You Meet in Heaven, Mitch Albom
  4. Night, Elie Wiesel
  5. Getting the Love You Want, Harville Hendrix
  6. Gilead, Marilynne Robinson
  7. Harry Potter and the Half-Blood Prince, JK Rowling
  8. Tipping Point, Malcolm Gladwell
  9. Angels & Demons, Dan Brown
  10. Marley & Me, John Grogan
  11. Guns, Germs and Steel, Jared Diamond
  12. The Year of Magical Thinking, Joan Didion
  13. Collapse, Jared Diamond
  14. Reviving Ophelia, Mary Pipher
  15. Dime! Uno, Fabian Samaniego
  16. A Million Little Pieces, James Frey
  17. The Devil in the White City, Erik Larson
  18. The Secret Life of Bees, Sue Monk Kidd
  19. The Grapes of Wrath, John Steinbeck
  20. Simon & Schuster Handbook for Writers, Lynn Troyka

The Catcher in the Rye

  1. The Catcher in the Rye, JD Salinger
  2. Cold Mountain, Charles Frazier
  3. His Needs, Her Needs, Willard F. Harley
  4. Parting the Waters, Taylor Branch
  5. Fast Food Nation, Eric Schlosser
  6. Rich Dad, Poor Dad, Robert T. Kiyosaki
  7. Holy Blood, Holy Grail, Michael Baigent, Richard Leigh, Henry Lincoln
  8. My Life, Bill Clinton
  9. Pride and Prejudice, Jane Austen
  10. The Road Less Traveled, Scott M. Peck
  11. Gone With the Wind, Margaret Mitchell
  12. The Old Man and The Sea, Ernest Hemingway
  13. March, Geraldine Brooks
  14. Blink, Malcolm Gladwell
  15. The Memory Keeper's Daughter, Kim Edwards
  16. Nickel and Dimed, Barbara Ehrenreich
  17. For Whom the Bell Tolls, Ernest Hemingway
  18. The Spirit Catches You and You Fall Down, Anne Fadiman
  19. How to Talk So Kids Will Listen, Adele Faber
  20. I Feel Bad About My Neck, Nora Ephron