Don't know how reliable this is, but I got this info from a Michael Jackson forum (without a link):

UK Top 40 Best Selling Catalogue Albums of 2007 :

1. Amy Winehouse – Frank *341,436
2. Phil Collins – Hits - *332,184
3. Snow Patrol – Final Straw - 145,000
4. James Blunt – Back To Bedlam - 140,000
5. The Proclaimers – The Best Of - 130,000
6. The Rolling Stones – Rolled Gold - The Very Best Of – *114,938
7. Diana Ross & The Supremes – The No.1’s – 105,000
8. Fleetwood Mac - Greatest Hits – 102,500
9. Genesis – Turn It On Again – The Hits – 101,000
10. KT Turnstall – Eye To The Telescope – 100,000
11. Rod Stewart – The Best Of – 99,500
12. Queen – Greatest Hits I II & III – 99,000
13. Ray Lamontagne – Trouble – 98,500
14. Bon Jovi – Cross Road – The Best Of – 96,000
15. Bruce Springsteen – Greatest Hits – 95,000
16. ABBA – Gold – Greatest Hits – 92,000
17. Rod Stewart – The Story So Far – 91,000
18. Michael Jackson – Number Ones – 90,000
19. Bob Marley & The Wailers – Legend – 89,000
20. Elvis Presley – Elvis – 30 Number 1 Hits – 88,000
21. Keane – Hopes & Fears – 89,000
22. Phil Collins – Love Songs – 88,000
23. Queen – Greatest Hits – 87,000
24. The Who – There & Then – 86,500
25. Barbara Streisand – The Essential – 83,000
26. Dusty Springfield – Hits Collection – 79,000
27. Razorlight – Up All Night – 77,000
28. Kasabian – Kasabian – 76,000
29. REM – In Time – The Best Of 1988-2003 – 75,000
30. Guns N’ Roses – Greatest Hits – 72,000
31. Katherine Jenkins – Second Nature – 71,000
32. Green Day – American Idiot – 70,000
33. Kylie Minogue – Ultimate Kylie – 69,000
34. Linkin Park – Hybrid Theory – 68,000
35. The Carpenters – Gold – Greatest Hits – 67,000
36. Pink Floyd – The Dark Side Of The Moon – *65,627
37. Lionel Richie – Back To Front – 64,000
38. Jack Johnson – In Between Dreams – 62,000
39. Madonna - The Immaculate Collection – 61,000
40. Led Zeppelin – Four Symbols – *60,859

*exact figures from MW

- Total artist album sales in 2007 = 106,033,425 (-14.3%)
- Total compilation album sales in 2007 = 30,453,028 (+0.2%)
- Total albums sold in 2007 = 138,067,371 (-10.8%)