Dream Theater - Images & Words (this was actually tough as hell)
Iron Maiden - Somewhere In Time (though A Matter Of Life And Death could well beat it some other day)
Opeth - Blackwater Park
Periphery - Juggernaut: Alpha & Omega
Wintersun - Wintersun
Between The Buried And Me - Colors (hands down)
Stam1na - Viimeinen Atlantis
Metallica - Master Of Puppets
Megadeth - Rust In Peace
The Faceless - Planetary Duality
Death - Symbolic
Insomnium - Shadows Of The Dying Sun
Meshuggah - ObZen
Ghost Brigade - Until Fear No Longer Defines Us
Agalloch - Ashes Against The Grain
Devin Townsend - Addicted
Sum 41 - Chuck
Coldplay - X&Y
Green Day - American Idiot
I've seen some very good lists here! Was kinda suprised how many people consider Mastodon to be one of their favorite bands.
Also, No Prayer For The Dying definitely kicks ass. And Virtual XI sucks