What? No Prong thread? Mainman Tommy Victor is one of the masters of crunchy Hardcore influenced Metal riffs and their sound that has straddled these genres. He has been highly influential in many areas including, Crossover, Industrial, Hardcore, Thrash, Punk and even without knowing- Nu Metal.
The closest that America has got to the Killing Joke sound without becoming a derivative and still maintaining their own particular sound.
Efficient, heavy and precise, Prong's music is sadly overlooked due to their reticence to align themselves with any particular genre.