Slipknot's self-titled is pretty original stuff, and one of the more furious albums in my collection (and yes I have plenty of albums by "real metal" bands like Darkthrone, Enslaved, Cryptopsy, Gorguts, Death, Carcass...). Great rhythm section too, the drummer seems to be the only one doing anything elaborate on his own but it all adds up. I dig it. Their other albums are nothing special, really.
I haven't heard much Dragonforce, but what I've heard just struck me as respectable but unremarkable power metal.