Hip Hop's Evolution From Old School Smooth To Unintelligible

In the 1980s, the best selling hip hop album was "Licensed to Ill" by the Beastie Boys. In the 1990s, it was "Life After Death" by Biggie Smalls. In the 2000s, it was "Speakerboxxx/The Love Below" by Outkast. In the 2010s so far, it's "Recovery" by Eminem.