I haven't heard too much Nu Metal that I like .

Two bands with killer riffs and great guitar tone ...THROTTLEROD and DIRTY POWER . I just wish they had better lead guitar playing . Other than that these guys have it down especially in the originality department . I'm tough to please . I can't take cookie monstar vocals and find the guitarists in most popular metal bands...like Lamb of God ...mediocre at best .
I'll take industrial metal fusion anyday over most post 80's metal . The Japanese have some seriously heavy music happening . Devil's Slingshot features Greg Howe . Keyboardist Tadashi Goto has a CD titled Innervisions that features guest guitarists shredding their asses off over some of the fastest , heaviest riffing I've heard in a long time .
John 5 has some cool heavy stuff .
FRAGILE is another Japanese band that will blow your Cd player apart . I have yet to be able to listen to an entire Cd .Way over the topin every department .