Based on sales for the week ending February 19, 2012

16. Catherine the Great
Robert K. Massie, Random House, $35, 9780679456728

17. Elizabeth the Queen
Sally Bedell Smith, Random House, $30, 9781400067893

18. Coming Apart
Charles Murray, Crown Forum, $27, 9780307453426

19. Ameritopia
Mark R. Levin, Threshold Editions, $26.99, 9781439173244

20. The Start-Up of You
Reid Hoffman, Ben Casnocha, Crown Business, $26, 9780307888907

21. The World of Downton Abbey
Jessica Fellowes, St. Martin's, $29.99, 9781250006349

22. The Swerve
Stephen J. Greenblatt, Norton, $26.95, 9780393064476

23. Boomerang
Michael Lewis, Norton, $25.95, 9780393081817

24. That Woman
Anne Sebba, St. Martin"s, $27.99, 9781250002969

25. Jack Kennedy
Chris Matthews, S&S, $27.50, 9781451635089

26. Guitar Zero
Gary Marcus, Penguin Press, $25.95, 9781594203176

27. Strategic Vision
Zbigniew Brzezinski, Basic Books, $26, 9780465029549

28. The Magic Room
Jeffrey Zaslow, Gotham, $27, 9781592406616

29. Ali in Wonderland
Ali Wentworth, Harper, $25.99, 9780061998577

30. Arguably
Christopher Hitchens, Twelve, $30, 9781455502776

31. Enemies
Tim Weiner, Random House, $30, 9781400067480

32. Rin Tin Tin
Susan Orlean, S&S, $26.99, 9781439190135

33. Hilarity Ensues
Tucker Max, Blue Heeler Books, $25.99, 9781451669039

34. Jesus Calling
Sarah Young, Integrity, $15.99, 9781591451884

35. Blue Nights
Joan Didion, Knopf, $25, 9780307267672

36. A History of the World in 100 Objects
Neil MacGregor, Viking, $45, 9780670022700

37. Guinness World Records 2012
Guinness, $28.95, 9781904994671

38. Fairy Tale Interrupted
Rosemarie Terenzio, Gallery, $25, 9781439187678

39. Plenty
Yotam Ottolenghi, Chronicle, $35, 9781452101248

40. Below Stairs
Margaret Powell, St. Martin's, $22.99, 9781250005441

41. Through My Eyes
Tim Tebow, Harper, $26.99, 9780062007285

42. Unorthodox
Deborah Feldman, S&S, $23, 9781439187005

43. The Greater Journey
David McCullough, S&S, $37.50, 9781416571766

44. Extra Virginity
Tom Mueller, Norton, $25.95, 9780393070217

45. That Used to Be Us
Thomas L. Friedman, Michael Mandelbaum, FSG, $28, 9780374288907

46. Is Everyone Hanging Out Without Me? (And Other Concerns)
Mindy Kaling, Crown Archetype, $25, 9780307886262

47. Food Rules
Michael Pollan, Maira Kalman (Illus.), Penguin Press, $23.95, 9781594203084

48. The New New Rules
Bill Maher, Blue Rider, $26.95, 9780399158414

49. Da Vinci's Ghost
Toby Lester, Free Press, $26.99, 9781439189238

50. The Obamas
Jodi Kantor, Little Brown, $29.99, 9780316098755