While I realize that Black Sabbath legitimately gets most of the credit for forging and defining the term "metal", when I think of true-blue, purebred metal, this is the album that immediately leaps to mind. The sound--unabashedly huge in scale and fantastical in scope--is just one successful element. The sequencing is brilliant; I challenge you to find a more perfect sonic mission statement than opening track "Hellion/Electric Eye". Placing the title track and "You've Got Another Thing Coming" towards the album's back end makes the whole piece feel more muscular overall. Plus, there's clearly a valid reason so many people can't resist the urge to rip off the iconic album art. Video for "Hellion/Electric Eye" is after the jump.