System of a Down
Metallica
Ozzy Osbourne
Black Sabbath
Iron Maiden
Deep Purple
Judas Priest
Van Halen
White Zombie
Wont list them all

Pantera, Metallica, S.O.A.D., Five Finger Death Punch, Megadeth,
Rise Against, Marilyn Manson, Disturbed, Korn, Killswitch Engage, Slipknot.
Etc.

Metallica
Ozzy Osbourne
Black Sabbath
Iron Maiden
Slipknot
Deep Purple
Judas Priest
Van Halen

It's sad to see what people think is metal these days.

Iron Maiden, Black Sabbath, Megadeth, Rainbow, Avenged Sevenfold, Metallica

Right now
Sodom and Skitsystem

Morbid Saint, Sepultura, Sodom, Bathory, and Nuclear Assault.

Lamb of God
Parkway Drive
I Killed the Prom Queen
As I Lay Dying
Slipknot
Amon Amarth
All that Remains
ISMFOF (not metal, but hardcore)
Killswitch Engage
In Flames
Metallica
Slayer

The Faceless.
Job For a Cowboy.
Suicide Silence.
The Devil wears Prada.
All That Remains.
In Dread Response.
Wintersun.
Hate Eternal.
Dream Theater.
Bring me the Horizon.
Metallica.
Bullet for my Valentine.
Pig Destroyer.
Naplam Death.
Cannibal Corpse.
As I lay Dying.
Van Halen.
Lamb of God.
Last Days of Humanity.
Devil Driver.
The Red Chord.
Six Feet Under.

And some more I can't remember.

Oh yeah forgot to add:
The Red Shore
Suicide Silence
Job For a Cowboy
Korn