My first full on metal albums were:
Deep Purple - Machine Head
Led Zeppelin
Black Sabbath
Iron Maiden
King Crimson
Alice Cooper - Killer (yes it was metal back then)
Judas Priest
Scorpians greatest hits (released in 79 I think)
Motley Crue - Too Fast For Love
I am younger than some of the users but my first metal album that i listened to was the Black album by Metallica. Then i listened to Master of Muppets.. then S & M.... That was my metallica stage.. My first new age metal cd that i bought is Deliverance by Opeth and Toyko Showdown by inflames...
if you consider it metal, Metallica's reload. if not, the Metallica's black album. and if not that, then it definitely was Metallica's RIDE THE LIGHTNING.