Pantera has 2 great albums and 1 that I used to listen for a while back then, but haven`t really even thought about much since (this being the Far Beyond Driven ofcourse). The rest of their stuff never meant much to me.
Slayer sucks...big time. That shouting really annoys me and their lyrics are just childish - even in heavy metal terms. And hey, this coming from a guy who lists Venom among his favorite bands :1orglaugh
Ok, I never paid much attention to them, but from the little I did, I got an impression that they were just some wanna-be-tough-guy posers without much sense of humour....