When I was 5 or so, I had a tape I stole from my aunt with Slayer, Metallica, Iron Maiden, and Mercyful Fate on it.
I remember getting a CD when I was in Denmark as a kid that had Darkthrone, Schattenheer, Celtic Frost, and some other now old school black metal stuff at a magazine stand in Odense. I came back to the US pretty much thinking I was the meanest motherf*cker in elementary school because I had that...
After that, I just kinda didn't listen to music for awhile, then I caught the buzz that was surrounding some of the Nu Metal bands that came out of no where (namely Slipknot), and I decided to dig out some of my old black metal stuff from Denmark and Germany and pick up where I left off.
All in all, I'm pretty sure Mercyful fate is what got me stuck to metal.