8. Black Sabbath (Ozzy)
By the end of the '70s, Black Sabbath were burned out. After years of pioneering the heavy metal sound on albums like Master of Reality and Paranoid, the band were weather-beaten and in desperate need of a break. While Tony Iommi eventually returned to his spot on the metal throne, frontman Ozzy Osbourne was getting a bit too hard to handle.
Going into recording for the albums Technical Ecstasy and Never Say Die, Ozzy was an absolute mess, abusing cocaine while trying to scrape together whatever vocal take would work for the track. Osbourne's health ended up getting so out of shape that he was eventually demoted when it came time to tour.
As the band hit the road in support of the album, Ozzy would usually be put on the side of the stage, with Iommi having the spotlight and pumping out riffs to compensate.
After years of shocking the masses with massive arena tours and one of the most maniacal frontmen in rock, Black Sabbath was now looking like a band being held together with safety tape. With all their commitments accounted for, Osbourne left Black Sabbath, with the band continuing on with Ronnie James Dio. Ozzy would eventually move on to a stellar solo career, but for a while, the world's finest heavy metal band was on its last legs.