Venom. They were among the first handful of bands I heard when I started getting into extreme metal 11-12 years ago along with Celtic Frost, Carcass, Morbid Angel, Death and one or two others, and they were the only one who did absolutely nothing for me. I had no problem appreciating them as influential, but I think they might just not have been what I was expecting or something. Dunno if it was the mediocre production, the barely competent musicianship or the fact that they just sounded kind of...goofy. In any case, I've had a copy of "Black Metal" lying around for years. I threw it on one day within the last year and something just clicked to the point that I was like, "hey, this is actually pretty cool." And it only took about a decade.