Hmm.... The obvious answer (for me) would be either Iron Maiden or Judas Priest, though in the 80's Metallica was very consistently excellent. Nobody championed heavy metal like Priest, but during the 80's Maiden had 6 mandatory albums to Judas Priest's 4 and Metallica's 4. I'm going with Iron Maiden.
To be fair, metal is broken up into how different types now? Let's just call them "pop metal". Hey, I used to look like them from '84 to '88. Let's just say I had the time of my life back then. (had more tang than you can imagine) But I understand the urge to knock bands like that. Anyway, I vote for Ozzy in the 80's.