mine would have to go to Judas Priest - Painkiller but its pretty difficult to pick one

One album stands out for me, Black Sabbath - Paranoid, every track is Fukn Epic!

Paranoid, Hand Of Doom, War Pigs, Electric Funeral, Fairies Wear Boots, Rat Salad and IRON MAN!!

Runners Up would be:

Iron Maiden - The Number Of The Beast
Black Sabbath - Self Titled

Oh Crap forgot Metallica! Ride The Lightning, Master Of Puppets both definitely up there

Ohh I have too many to write down.

Iron Maiden - Killers
Iron Maiden - The Number Of The Beast
Trivium - Shogun
Metallica - Master Of Puppets
Metallica - Black Album
Parkway Drive - Horizons
Parkway Drive - Killing With A Smile
System Of A Down - Toxicity
System Of A Down - Mexmerize
System Of A Down - Hypnoize

Only did albums that I own

Master of Puppets
Back in Black
Appetite For Destruction (not really metal though)

horizons, parkway

best ever

Tough Decision But - The Number Of The Beast IRON MAIDEN is My suggestion

Agree heavily with Hendo. Paranoid has gotta be THE definitive metal album.

With Number of the Beast however, I personally think it's a little overrated. It's a great album, but I think it's nowhere near one of Maiden's best albums (Powerslave is , very closely followed by Caught Somewhere in time and 1st album)

My personal Faves (in no order):
Metallica- Ride the Lightning
Iron Maiden- Powerslave
Black Sabbath- Paranoid; Master of Reality
Dio- Holy Diver
Megadeth- Rust in Peace
Slayer- Reign in Blood
Opeth- Blackwater Park

Fair few more but the first three are probably most listened to.

hmmm tough indeed. so many.. but here's a few of them

metallica- master and ride the lighning
machine head- burn my eyes
Mastodon-Blood mountain
In flames-clayman
Iron maiden-seventh son
Machine head-the blackening
Trivium-ascendancy
Sepultura- Roots
mastodon-leviathan
pantera-vulgar display of power

i reckon the upcoming mastodon album crack the skye could be huuge

There are too many.