Here's my picks.. I'm now 30 years old and have been into metal since the 80's. So all of the below albums I was into when they originally came out. I know GnR isn't metal, but man when it came out, it was brilliant.
Was this disclaimer to stop us beating you up for posting such a shit list?
Anyway, I'll state the obvious for all of you:
AC/DC - Back In Black
Black Sabbath - Black Sabbath, Paranoid, Heaven & Hell
Deep Purple - Machine Head
Iron Maiden - Iron Maiden, The Number Of The Beast
Judas Priest - Painkiller
Michael Schenker Group - first two
Rainbow - Rising
Whitesnake - Ready & Willing, Come An' Get It