i agree with preacher...they kinda slid downhill after the black album. i wont really say they "sold out" i just think they tried a little too hard to get away from their roots. ride the lightning or ...and justice for all, two of the best metal albums ever made IMO. i frikkin played the songs off justice till my fingers bled. especially "and justice for all" (****in BAD *** song) and "harvester of sorrow".
slipknot i never could get into...they will have these moments where everything is happening right, and youre like "**** this song is like a fist in my face" and every one is playing the same time, then all of the sudden they ruin it, go out of time, get dischordant, whatever....but they totally know how screw up a good song IMO. stone sour, which is the baby of corey taylor and joel ekman (used to drum for slipknot), is much better than slipknot IMO. they are much more cohesive as a band, for one thing, and most of their stuff is just as heavy.