Billboard and Nielsen SoundScan have just released a list of the top-selling albums of the SoundScan era (1991-2011). Coming in at No. 1 with more than 15 million units sold to date is Metallica's self-titled 1991 disc, aka The Black Album.

Metallica are the most successful band in metal history regarding album sales. The thrash giants have sold more than 100 million records worldwide. Metallica also came in at No. 4 on SoundScan's top-selling artists of the past 20 years, only being topped by Garth Brooks, the Beatles and Mariah Carey.

The Black Album topped the charts in eight countries and delivered some of metal's most legendary tracks such as 'The Unforgiven,' 'Nothing Else Matters' and 'Enter Sandman.'

Metallica recently celebrated their 30th anniversary as a band by four small club dates for their fan club members in San Francisco. Some of the biggest names in metal came out to share the stage with Metallica during the four-day celebration such as Ozzy Osbourne and Rob Halford as well as former Metallica members Jason Newsted and Dave Mustaine.

Metallica are set to release a B-sides album of songs recorded during the 'Death Magnetic' sessions on Jan 30. titled 'Beyond Magnetic.'

Top 10 Highest-Selling Albums of the Nielsen SoundScan Era

(1991 – 1/1/2012)

Artist Units Sold
1 'Metallica,' Metallica 15,735,000
2 'Come On Over,' Shania Twain 15,513,000
3 'Jagged Little Pill,' Alanis Morissette 14,714,000
4 'Millennium,' Backstreet Boys 12,168,000
5 '1,' Beatles 11,985,000
6 Soundtrack, 'Bodyguard' 11,829,000
7 'Supernatural,' Santana 11,772,000
8 'Human Clay,' Creed 11,574,000
9 'No Strings Attached,' N Sync 11,122,000
10 'Falling Into You,' Celine Dion 10,790,000