Both. The rapper emerges as the top-selling artist of the past 10 years, and the Fab Four have bragging rights to the best-selling album.
With 32.2 million copies sold, Eminem leads the pack in overall album sales, followed by The Beatles with 30 million, according to Nielsen SoundScan, which releases its decade tabulations today. Data were tallied through Nov. 1, and though figures could rise through Dec. 31, they won't alter the rankings.
source
USA Today
Note: This is absolutely true and it make sense!
(comment)---that's why the Beatles' accomplishment is so amazing. the top album of the decade for a band that broke up 40 years ago! they broke up but never really went away. their shelf life is probably permanent.