The fact that RJD2 stands for Ronnie James Dio the second makes me overflow with glee.
In addition:
Non-Phixion (download "The CIA is Trying to Kill Me", "I Shot Reagan", or "Black Helicopters" and tell me that they don't eat your face. How can you not love a group with the lyric, "I reign in blood, just like Slayer did in '86"?)
I can't believe no one mentioned Knowledge Reigns Supreme Over Nearly Everyone. You should be fucking ashamed.
Another note about Non-Phixion. In their song "The CIA is Still Trying to Kill Me", which is a metal remix of the previously mentioned song (complete with Dino from Fear Factory on guitar), there are references to Slayer, Megadeth, Black Sabbath, Metallica, and I seem to remember an Anthrax reference but I may be wrong. Also, their logo is modeled after the Voivod logo. Bottom line: Non-Phixion is really, really awesome, and they're metalheads, which makes them orgasmic.