Before the end of '03 I was mostly into classical and classic rock, while I despised anything that had to do with MTV and that scene (which my older sister was enslaved to). I was also a fan of Dragonball Z and I watched it every day on Cartoon Network. About that time I was introduced to P2P apps such as Kazaa and Ares, with which I downloaded Dragonball Z video clips. Among these video clips were music videos set to Linkin Park and Limp Bizkit songs. Through these videos I got into Nu-Metal. It was mainly those bands, plus System of a Down and Slipknot that I would download songs using Kazaa.
Towards that same time I was on the high school wrestling team. Every day at practice they would play heavy music on the radio, including Metallica and Rammstein. So these bands were added to my rotation of illegally downloaded and burnt CD-R's that I listened to for over a year.
My path to extreme metal started in Spring '05 when I found this site called Rocktoons.com, which does caricatures of rock and metal bands. I was browsing through it and came up a caricature of this band called The Kovenant. Intrigued, I checked them out but couldn't get many of their songs off of Kazaa. Because of this, I was forced to buy my first CD, The Kovenant's SETI. As I explored this band's back-catalogue I got more and more accustomed to extreme vocals.
Fall of '05 my friend Nick (Cookiecutter) introduced me to Hypocrisy, the first death metal band I ever heard and liked. I still remember when he sent me on an errand to pick up Hypocrisy's Virus album.
My path to black metal was set by The Kovenant and Wikipedia. Looking at the band's Wikipedia article, I saw that former members of the band played in Arcturus. So I got into Arcturus, and by the same means discovered Borknagar, who remain to this day my favorite (black) metal band. My first extreme album purchase was Borknagar's Quintessence, which still shines at the top of my list.