1 . Madonna -- Immaculate Collection :: 3,565,000
2 . Shania Twain -- Come On Over :: 3,360,000
3 . Dido -- No Angel :: 3,060,000
4 . Leona Lewis -- Spirit :: 3,050,000
5 . Amy Winehouse -- Back To Black (incl. Deluxe Edition) :: 3,045,000
6 . Dido -- Life For Rent :: 2,860,000
7 . Alanis Morissette -- Jagged Little Pill :: 2,600,000
8 . Lady Gaga -- Fame / Fame Monster :: 2,540,000
9 . Norah Jones -- Come Away With Me :: 2,500,000
10 . Tracy Chapman -- Tracy Chapman :: 2,445,000
11 . Whitney Houston -- Whitney :: 2,240,000
12 . Duffy -- Rockferry :: 2,180,000
13 . Tina Turner -- Simply The Best :: 2,130,000
14 . Celine Dion -- Falling Into You :: 2,115,000
15 . Kylie Minogue -- Kylie: The Album :: 2,100,000
16 . Celine Dion -- Let's Talk About Love :: 1,995,000
17 . Madonna -- True Blue :: 1,980,000
18 . Christina Aguilera -- Stripped :: 1,950,000
19 . Susan Boyle -- I Dreamed A Dream :: 1,880,000
20 . Katie Melua -- Call Off The Search :: 1,865,000
21 . Celine Dion -- Colour Of My Love :: 1,850,000
22 . Eva Cassidy -- Songbird :: 1,840,000
23 . Pink -- Missundaztood :: 1,815,000
24 . Avril Lavigne -- Let Go :: 1,765,000
25 . Adele -- 21 :: 1,755,000
26 . Rihanna -- Good Girl Gone Bad :: 1,740,000
27 . Kylie Minogue -- Fever :: 1,710,000
28 . Madonna -- Ray Of Light :: 1,710,000
29 . Whitney Houston -- Greatest Hits :: 1,660,000
30 . KT Tunstall -- Eye To The Telescope :: 1,645,000
31 . Madonna -- Like A Virgin :: 1,640,000
32 . Madonna -- Music :: 1,625,000
33 . Kelly Clarkson -- Breakaway :: 1,545,000
34 . Mariah Carey -- Music Box :: 1,505,000
35 . Macy Gray -- On How Life Is :: 1,410,000
36 . Beyonce -- I Am Sasha Fierce :: 1,395,000
37 . Tina Turner -- Foreign Affair :: 1,380,000
38 . Gabrielle -- Dreams Can Come True - Greatest Hits :: 1,370,000
39 . Barbra Streisand -- Love Songs :: 1,365,000
40 . Sade -- Diamond Life :: 1,350,000
41 . Pink -- I'm Not Dead :: 1,350,000
42 . Madonna -- Confessions On A Dancefloor :: 1,345,000
43 . Florence + The Machine -- Lungs :: 1,340,000
44 . Celine Dion -- All The Way - A Decade Of Song :: 1,325,000
45 . Katie Melua -- Piece By Piece :: 1,305,000
46 . Kate Bush -- Whole Story :: 1,305,000
47 . Alison Moyet -- Alf :: 1,280,000
48 . Rihanna -- Loud :: 1,280,000
49 . Annie Lennox -- Diva :: 1,270,000
50 . Madonna -- Like A Prayer :: 1,270,000
Credit to: Hendra