It wasn´t before 1984, when I was already 16, that I got into metal. Before that, my favourite artists had been Elvis Presley and Abba (and I had also listened to some other pop stuff). Then, in the beginning of 1984, I had bought Pat Benatar´s "Live From Earth Album". Well, the music on this album doesn´t qualify as metal, but many of the live songs were definitely heavier than anything I´d listened to before and I really liked especially the heavier parts on this album. In late spring 1984 I bought Lita Ford´s "Dancin´On The Edge" (after I had seen her on TV with the song "You Gotta Let Go") and I really loved this album way back then. Finally, it must have been somewhere in autumn 1984, I had started listening to the "Monday Rock Show" on BFBS. On one show - I don´t remember if it was the first one I listened to or another one afterwards - they played "Fight Fire With Fire". It was sooo fucking brilliant - like a musical revelation! So on Christmas 1984, I got "Ride The Lightning". I loved this album so much that I listened to it on a nearly daily basis for much more than a year, and if there´s a Metallica-album I still listen to today (though only rarely), it´s this one. (BTW, Metallica were also the first band I saw live - in January 1987 with opening act Metal Church.)
After this experience, I listened nearly exclusively to metal until 1989. There were always new interesting bands to discover: Helloween, Fates Warning, Agent Steel, Anthrax, Megadeth, Helstar, Metal Church, Overkill, Détente, Testament, Voivod, Hades, Heathen, Flotsam & Jetsam, Mekong Delta, Sieges Even, Forbidden, Coroner, Hexenhaus, Candlemass, Anacrusis and some more. Just thinking about these times conjures up feelings of nostalgia. Actually, I´ve never really cared much about the really "big" names in metal, but I was more into speed, thrash, power and some progressive metal. (Well, I still am, though far less than I once used to be, and most of the albums from these genres that I still listen to are from the eighties.) And when Metallica became really big in 1991, I had already lost interest in them. I stopped buying their albums after "...And Justice For All", which hadn´t impressed me much. Ok, "One" is probably one of their best songs, but the sound on "...And Justice..." is too "dry" for my taste and most of the songs just don´t do it for me. And considering how Jason Newsted´s bass had sounded on Flotsam & Jetsam´s "Doomsday For The Deceiver" made this album even more disappointing!
Ok, as this thread is about "Your first hit of metal", I guess I´ve already gone too far now, so I better stop here.
Well, one final word about the year 1991, which was mentioned in some posts: it was also the year in which my favourite metal album of all times was released: "Within The Veil" by Fear Of God.