I got the list from the
Guardian. I've only read 20 of them and seven of those are Harry Potter. This covers about 90% of books sold in the UK since 1998.
1. Da Vinci Code,The - Brown, Dan
2. Harry Potter and the Philosopher's Stone# - Rowling, J. K.
3. Harry Potter and the Chamber of Secrets# - Rowling, J. K.
4. Angels and Demons# - Brown, Dan
5. Harry Potter and the Order of the Phoenix - Rowling, J. K.
6. Harry Potter and the Half-blood Prince:Children's Edition - Rowling, J. K.
7. Harry Potter and the Deathly Hallows - Rowling, J. K.
8. Harry Potter and the Prisoner of Azkaban# - Rowling, J. K.
9. Twilight# - Meyer, Stephenie
10. Harry Potter and the Goblet of Fire - Rowling, J. K.
11. Deception Point# - Brown, Dan
12. New Moon# - Meyer, Stephenie
13. Lovely Bones,The# - Sebold, Alice
14. Digital Fortress# - Brown, Dan
15. Curious Incident of the Dog in the Night-time,The# - Haddon, Mark
16. Eclipse# - Meyer, Stephenie
17. Girl with the Dragon Tattoo,The:Millennium Trilogy# - Larsson, Stieg
18. Kite Runner,The# - Hosseini, Khaled
19. Time Traveler's Wife,The - Niffenegger, Audrey
20. World According to Clarkson,The - Clarkson, Jeremy
21. Atonement# - McEwan, Ian
22. Lost Symbol,The - Brown, Dan
23. Short History of Nearly Everything,A - Bryson, Bill
24. Breaking Dawn - Meyer, Stephenie
25. Harry Potter and the Goblet of Fire - Rowling, J. K.
26. Harry Potter and the Deathly Hallows - Rowling, J. K.
27. Girl Who Played With Fire,The:Millennium Trilogy# - Larsson, Stieg
28. Child Called It,A - Pelzer, Dave
29. No.1 Ladies' Detective Agency,The:No.1 Ladies' Detective Agency S. - McCall Smith, Alexander
30. You are What You Eat:The Plan That Will Change Your Life - McKeith, Gillian
31. Man and Boy - Parsons, Tony
32. Birdsong - Faulks, Sebastian
33. Labyrinth - Mosse, Kate
34. Island,The - Hislop, Victoria
35. Life of Pi - Martel, Yann
36. Dr. Atkins' New Diet Revolution:The No-hunger, Luxurious Weight Loss P - Atkins, Robert C.
37. Tales of Beedle the Bard,The - Rowling, J. K.
38. Captain Corelli's Mandolin - De Bernieres, Louis
39. Delia's How to Cook:(Bk.1) - Smith, Delia
40. Gruffalo,The# - Donaldson, Julia
41. Eats, Shoots and Leaves:The Zero Tolerance Approach to Punctuation - Truss, Lynne
42. Northern Lights:His Dark Materials S. - Pullman, Philip
43. Interpretation of Murder,The - Rubenfeld, Jed
44. Girl Who Kicked the Hornets' Nest,The:Millennium Trilogy - Larsson, Stieg
45. Bridget Jones: The Edge of Reason - Fielding, Helen
46. Short History of Tractors in Ukrainian,A - Lewycka, Marina
47. Alchemist,The:A Fable About Following Your Dream - Coelho, Paulo
48. Notes from a Small Island - Bryson, Bill
49. Boy in the Striped Pyjamas,The# - Boyne, John
50. Stupid White Men:...and Other Sorry Excuses for the State of the Natio - Moore, Michael
51. Jamie's 30-minute Meals - Oliver, Jamie
52. Broker,The - Grisham, John
53. Bridget Jones's Diary:A Novel - Fielding, Helen
54. Very Hungry Caterpillar,The:The Very Hungry Caterpillar - Carle, Eric
55. Thousand Splendid Suns,A - Hosseini, Khaled
56. Sound of Laughter,The - Kay, Peter
57. Jamie's Italy - Oliver, Jamie
58. Small Island# - Levy, Andrea
59. Memory Keeper's Daughter,The - Edwards, Kim
60. Billy Connolly - Stephenson, Pamela
61. House at Riverton,The - Morton, Kate
62. Harry Potter and the Order of the Phoenix# - Rowling, J. K.
63. Nigella Express - Lawson, Nigella
64. Memoirs of a Geisha - Golden, Arthur
65. Delia's How to Cook:(Bk.2) - Smith, Delia
66. Subtle Knife,The:His Dark Materials S. - Pullman, Philip
67. Jamie's Ministry of Food:Anyone Can Learn to Cook in 24 Hours - Oliver, Jamie
68. Guinness World Records 2009:2009 -
69. Why Don't Penguins' Feet Freeze?:And 114 Other Questions -
70. Jamie at Home:Cook Your Way to the Good Life - Oliver, Jamie
71. White Teeth - Smith, Zadie
72. Devil Wears Prada,The - Weisberger, Lauren
73. At My Mother's Knee ...:and Other Low Joints - O'Grady, Paul
74. No Time for Goodbye - Barclay, Linwood
75. "Times" Su Doku,The:The Utterly Addictive Number-placing Puzzle:(Bk. 1 -
76. Chocolat - Harris, Joanne
77. Return of the Naked Chef,The - Oliver, Jamie
78. Angela's Ashes:A Memoir of a Childhood - McCourt, Frank
79. Schott's Original Miscellany - Schott, Ben
80. Dreams from My Father:A Story of Race and Inheritance - Obama, Barack
81. Dangerous Book for Boys,The - Iggulden, Conn & Iggulden, Hal
82. To Kill a Mockingbird# - Lee, Harper
83. Harry Potter and the Half-blood Prince - Rowling, J. K.
84. Summons,The - Grisham, John
85. Lost Symbol,The - Brown, Dan
86. Catcher in the Rye,The - Salinger, J.D.
87. I Can Make You Thin - McKenna, Paul
88. Happy Days with the Naked Chef - Oliver, Jamie
89. Brick Lane - Ali, Monica
90. Anybody Out There? - Keyes, Marian
91. Undomestic Goddess,The - Kinsella, Sophie
92. Book Thief,The# - Zusak, Markus
93. I Know You Got Soul - Clarkson, Jeremy
94. Sharon Osbourne Extreme:My Autobiography - Osbourne, Sharon
95. Guinness World Records 2010 -
96. Amber Spyglass,The:His Dark Materials S. - Pullman, Philip
97. Can You Keep a Secret? - Kinsella, Sophie
98. Down Under - Bryson, Bill
99. Spot of Bother,A - Haddon, Mark
100. Dear Fatty - French, Dawn