Well... I got a lot, so here's a just a few of my favorites (one song per band):
Heavy Metal: "Godzilla"- Blue Oyster Cult, "We're Not Gonna Take It"- Twisted Sister, "The Show Must Go On"- Queen, "Dreams"- Van Halen, "Smoke on the Water"- Black Sabbath, "School's Out"- Alice Cooper, "The Boys are Back in Town"- Thin Lizzy
Alternative Metal: "Fly from the Inside"- Shinedown, "Scum of the Earth"-Rob Zombie, "Animal I Have Become"- Three Day's Grace, "Enemy"- Sevendust, "One Day Remains"- Alterbridge, "Crash"- Papa Roach
Glam Metal: "Bark at the Moon"- Ozzy Osbourne, "Mr. Roboto"- Styx, "Civil War"- Guns N' Roses
Nu Metal: "No More Sorrow"- Linkin Park, "Bring Me To Life"- Evanesence, "Land of Confusion"- Disturbed, "Immortal"- Adema, "Chop Suey!"-System of a Down, "Headstrong"- Trapt
Thrash Metal: "The Unforgiven"- Metallica, "Back in the Day"- Megadeth
Industrial Metal: "This is Halloween"- Marilyn Manson, "Timelessness"- Fear Factory, "Nothing for me Here"- Dope
Power Metal: "Fantasmic"- Nightwish, "Replica"- Sonata Arctica (The original version that is, not the remake)
Also, "Through the Fire and Flames" by Dragon Force, whatever category that song is in.