Up until recently Billboard put albums that were over 18 months old on a separate sales chart from the much talked about Billboard 200. Those releases were featured on the "catalog" album chart. This means albums that have a shelf life and still sell after their initial year of release. Looking at Neilsen SoundScan numbers from 2008 (the last year we have the data for) shows us that catalog and what they term deep catalog albums outsold current release; 307.7 million to 249.6 million respectively. In fact, rock related genres (Rock, Metal, Alternative) out sold all other genres tracked by SoundScan combined: 271 million to 261.9 million.

The Billboard chart did not include any sales data, they just ranked them based on what we assume were their sales and seven rock related releases dominated the Top 10, with only one country release, one pop release and one reggae release making the Top 10.

Here is Top 10

1. Bob Seger & The Silver Bullet Band � Greatest Hits
2. Bob Marley And The Wailers � Legend: The Best of Bob Marley and the Wailers
3. Pink Floyd � Dark Side of the Moon
4. Metallica � Metallica
5. The Beatles � 1
6. Queen � Greatest Hits
7. Tim McGraw � Greatest Hits
8. AC/DC � Back in Black (for some strange reason is also listed at No 45)
9. Michael Jackson � Number Ones
10. Journey � Journey's Greatest Hits

- Check out the full Top 50 Catalog Albums of the Decade List here