I suppose the answer will vary, depending on what you consider "metal." When I was a kid, I really liked Van Halen, Journey and Rush. Things evolved for me from there toward the hair bands of the late 80's and early 90's. It wasn't until I got a copy of Metallica's "...And Justice for All" on cassette tape that I really started listening to the heavier stuff. A friend of mine got me listening to Dream Theater in high school. By then, I started getting more into Iron Maiden and Judas Priest, as well as more current prog like Queensryche. I first heard Symphony X when a coworker brought a tape of their self titled album into work.