I can't believe I've been left out of this conversation...
First of all Lateralus kicks ass; and Schism is an awesome live song. I don't remember too much of that concert. Too many bongs floating around in my section. Meshuggah did suck.
As far as loud stuff goes, I'd say Black Sabbath (before Ozzy left, everything else after is just crap in my opinion; Tony Iommi rocks though)... when I was in my early teens I had my Metallica phase... I really like "No Leaf Clover" from the S&M album, but none of their newer stuff appeals to me.
Some punk too, like the Clash (semi-loud, but great nonetheless) and Sex Pistols...
I saw Godsmack one time... they were ok, but I totally lost respect for them after the Grammy's. Did you see the lame clap that Sully gave Coldplay... what's up with the cameramen always picking random artists reactions to things... who cares what Godsmack thinks about anything. Just because you served two days in jail Mr. Urna, doesn't give you street cred, and certainly doesn't make your music better. Go smoke your sweet leaf and stop complaining about Greed, when you make millions of dollars... asshole.