Wow Alyssa, I love your list! I think I'll put it on my iPod!
Myself being a metalhead (maybe slightly older?), I am more than partial to...
Slayer... anything from Hell Awaits, Reign in Blood or the EP Haunting the Chapel/ Live Undead is sure to calm me down.. .especially Raining Blood, Chemical Warfare and Angel of Death...
1st album by Rage against the Machine... especially Bullet in the Head
Anthrax, though they are often too nice, he he he... but Sound of White Noise contains some pretty intense songs (Sodium Penthotal...1000 Points of Hate... Packaged Rebellion...Only) which put my mood on ice...
Oh, and how can I forget about the 1st Metallica album... KIll 'em All !!