1. Bruno Mars - Unorthodox Jukebox - 4.0m (total: 4.5m)
2. Justin Timberlake - The 20/20 Experience - 3.8m
3. Daft Punk - Random Access Memories - 3.1m
4. Eminem - The Marshall Mathers LP 2 - 2.9m
5. Pink - The Truth About Love - 2.9m (total: 5.3m)
6. One Direction - Midnight Memories - 2.5m
7. Mumford & Sons - Babel - 2.4m (total: 5.1m)
8. One Direction - Take Me Home - 2.4m. (total: 5.3m)
9. Imagine Dragons - Night Visions - 2.3m
10. Michael Bublé - To Be Loved - 2.3m

11. Taylor Swift - Red - 1.9m (total: 5.7m)
12. Macklemore & Ryan Lewis - The Heist - 1.9m
13. Rihanna - Unapologetic - 1.9m (total: 3.5m)
14. Katy Perry - Prism - 1.8m
15. Soundtrack - Les Misérables 1.7m
16. Lumineers - Lumineers - 1.7m
17. Drake - Nothing Was The Same - 1.7m
18. Adele - 21 - 1.6m (total: 26.1m)
19. Luke Bryan - Crash My Party - 1.6m
20. Jay-Z - Magna Carta... Holy Grail - 1.5m

If an album was released in 2012 and I haven't added that to it's total, it's because it failed to make last year's WW YE Top 40 and so it's sales for that year are unknown to me.

Source: http://www.mediatraffic.de/year-end-albums.htm

21. Emeli Sande - Our Version Of Events - 1.5m (total: 3.4m)
22. Florida Georgia Line - Here's To The Good News - 1.4m
23. Lana Del Rey - Born To Die - 1.4m (total 4.3m)
24. Beyonce - BEYONCE - 1.4m
25. Lady Gaga - ARTPOP - 1.3m
26. Passenger - All The Little Lights - 1.3m
27. Stromae - Racine Carrée - 1.3m
28. David Bowie - The Next Day - 1.2m
29. Miley Cyrus - Bangerz - 1.2m
30. Blake Shelton - Based On A True Story - 1.2m

31. Depeche Mode - Delta Machine - 1.1m
32. Fun. - Some Nights - 1.1m (total: 2.7m)
33. Soundtrack - Pitch Perfect - 1.1m
34. Michael Bublé - Christmas - 1.1m (total: 8.3m)
35. Robbie Williams - Swings Both Ways - 1.1m
36. Robin Thicke - Blurred Lines - 1.1m
37. One Direction - Up All Night - 1.1m (total: 5.2m)
38. Celine Dion - Loved Me Back To Life - 1.1m
39. Lorde - Pure Heroine - 1.1m
40. Ed Sheeran - Plus - 1.0m (total: 3.7m)

Source: http://www.mediatraffic.de/year-end-albums.htm

Edit: Also Bruno's total is incorrect, it should be 4.9m.