I try to listen for talent, and usually that just happens to be guitar work. My dad is a huge fan of the stuff you've listed (Killaman), and that gradually increased in "heaviness", Iron Maiden to Slipknot to Lamb of God to the stuff I listen to now. My favorite band, Between the Buried and Me, incorporates many influences and genres into their music. They can be one of the heaviest bands I've heard, or a soft rock with intricate guitar work. All of their songs are really long, too ._.
http://www.youtube.com/watch?v=VdGJyv8vr6g#t=05m52shttp://www.youtube.com/watch?v=13wM7Iqdzb8#t=08m36sAbout that "actual metal" comment, everything has an origin, or an influence. I could say that Iron Maiden and Metallica aren't "actual metal" and that Black Sabbath and Led Zeppelin did it first, hell even Judas Priest but I don't because Maiden was a new genre. If I'm talking about music I like in general I label it as "metal", like I did with this topic, but normally I'll call it by it's more specific name, be it deathcore or mathcore (I know you probably think they're the same). I've heard that the music I listen to all sounds the same so many times.. what about mainstream hard rock? What about Hammet's solos in every Metallica song? I think
they sound the same.
*EDIT*
Unless you listen like 5 minutes past the time where the links start, it shouldn't be anything you have trouble listening to.