Paranoid (1971)

 Not only is this the best Black Sabbath album, it is one of the best heavy metal albums ever. It includes the legendary singles "Iron Man" and "Paranoid" and is a defining moment in the history of heavy metal. Listen to this album and you will hear why every heavy metal band in history is descended from Black Sabbath. They defined a genre, and this album defined them. 

 Master Of Reality (1971)

It's hard to believe that a band could release its two best albums in the same year, but that's exactly what Black Sabbath did. This was the follow up to Paranoid. It was only 8 songs long and 2 of those were brief instrumentals, but it showcased the brilliant guitar of Tony Iommi. It's also more complex than their first two albums and shows a marked musical progression.

Sabbath Bloody Sabbath (1973)

Their fifth album has something for everyone. There's another one of Iommi's instrumentals, and on the other end of the spectrum is the crushing title track. Ozzy's vocals are some of his best, and the production is also very good. The addition of Rick Wakeman from Yes on keyboards got mixed reviews at the time, but he did add something different to the mix.

Heaven And Hell (1980)

It's pretty difficult to replace a legend like Ozzy Osbourne, but doing it with a vocalist the caliber of Ronnie James Dio was a great move. The band sounded rejuvenated and Dio's vocal range allowed them to do a few more things. Every song is really good, but the title track is exceptional.

 Vol. 4 (1972)

Their fourth album showed both ends of the musical spectrum. On the softer side is the ballad "Changes," which had a lot of commercial success. On the other side of the coin is "Supernaut," a really fast and intense song. It tells you just how good Sabbath was when this album is only their fourth best.