Dark Tranquillity
Hypocrisy

Decapitated
Decapitated
Decapitated


...And Moonsorrow.

We actually had an awesome line-up last year here on Mexico, a funny proof that great things can happen at third world countries too, at least sometimes, LOL. Just ignore the first band... that was some of the shitiest things I've ever heard/seen.

Atreyu (yuck!)
Morbid Angel
Carcass
Iron Maiden (considering they don´t come too often to latin-american countries, it was a blast!)

All in one day, one stage! One of the greatest days...

Pitchshifter
Godlfesh
Atari Teenage Riot
Carcass

OPETH
HYPOCRICY
LAMB OF GOD
NILE

and I'll be the host

Behemoth
Nile
Incantation
Autopsy

also old kataklysm

Machine Head
Chimaira
Lamb of God
Slipknot

or

All Shall Perish
Whitechapel
August Burns Red
Parkway Drive

Soulfly
Machine Head
Turisas
Amon Amarth

Omg

Blind Guardian
Emperor
Ihsahn
Windir
Agalloch

I know they're not exactly the same genre of metal, but it would still be cool.

Nile
Obscura
Amon Amarth
Necrophagist

and Rammstein (But they don't belong on this particular list)