I am very bored and wanted to list all the bands (that I can remember) that I've seen.
But first, please check out this designer, best band shirts ever! http://www.filipesurvival.com/

Anyways, let's see if I can remember this. I'll try and do in order of when I saw them.

Ozzy @ the Saddledome
Megadeth w/ Exodus @ Reds
Megadeth w/ Fear Factory & Anthrax @ the Corral
System of a Down w/ Bad Acid Trip & Hatebreed @ the Saddledome
Rob Zombie w/ Anthrax @ the Corral
Guns 'n' Roses w/ Helmet & Sebastian Bach @ the Saddledome
Heaven & Hell w/ Down & Megadeth (Down never ended up playing) @ the Saddledome
Taste of Chaos '08: Blessthefall, Bullet For My Valentine, Atreyu & Avenged Sevenfold (BFMV canceled) @ the Corral
Megadeth w/ High on Fire, Job for A Cowboy, Children of Bodom & In Flames @ the Corral
As I Lay Dying w/ Evergreen Terrace, August Burns Red & Misery Signals @ Mac Hall
Warped Tour '08: Bring Me the Horizon, All That Remains & Evergreen Terrace @ Race City
AC/DC w/ the Answer @ GM Place
Metallica w/ the Sword & Lamb of God @ the Saddledome
Taste of Chaos '09: Ninjaspy, Cancer Bats, Four Year Strong, Pierce the Veil, Bring Me The Horizon & Thursday @ Mac Hall
Slayer & Megadeth w/ Suicide Silence & Machine Head @ the Saddledome
Warped Tour '09: the Devil Wears Prada, A Day To Remember, Underoath, Gallows & Escape The Fate @ Race City

That was fun lol.
But I would KILL to see:

I Killed The Prom Queen
It Dies Today
Parkway Drive
Architects
Miss May I
Bullet For My Valentine

Oh man the list just goes on. XD