44. System of a Down, 'Toxicity'
The most political metal record of the decade somehow managed to be the weirdest and most intimate as well. Paired with Rick Rubin, the Armenian-American band exploded time signatures and conventional rock-speak, denouncing drug laws and druggies, praising spirituality while cracking dirty jokes. Musically, System crushed, juicing prog-metal with Eastern rhythms and surprising beauty — most amazingly on "Chop Suey!," a breathtaking rant ballad haunted by suicide and religious abandonment. Neither System nor any other metal band has come close to replicating Toxicity, which is as mind-boggling today as it ever was.