" With the thirty-seven keys of Tzeentch, we open the way for our brothers. With the thousand whispers of Slaanesh, we call to them. With the twelve plagues of Nurgle, we fell their enemies. And with the mighty axe of Khorne, we cut open the world for them. "
My personal favourite is the last wretched gurgle fleeing from the twisted mouths of the servants of She Who Thirsts as their mind and form both melt and burn by my will. Other than that though, it's: "The Imperium is a weak old man, ready and waiting to be broken apart by his vengeful sons." -Lufgt Huron, The Tyrant of Badab.
I have slain many enemies, and won many battles and I tell you there is no great secret to success in war, no subtle trick of strategy that has saved my foes -- I seek out the enemy, attack as soon as I am able and with all the force at my command, rend his soldiers and smash his fortresses, leave only corpses behind me and then move on —Khârn Unlike you, whelp, I once walked the same ground as your idol. I breathed the same air as him. And I tell you this, without lie or artifice. He never wanted to become what you have made him! He did not wish to be your god-thing. He abhorred such ideals! The slavery of your crippled, blind Imperium would sicken him, if he had eyes to see it. Fabius Bile
"You kept that mule Kor Phaeron. Russ kept his kin-friends. The Lion kept Luther. Humans - brothers and foster fathers - saved and raised into Legion ranks. But not me. Not Angron, no. Did the Emperor teleport his gold-wrapped Custodians down to help me and my army? No. Did he free the War Hounds and order them to battle, fight alongside me? No. Did he save my brothers and sisters the way he spared and honoured the Lion's closest kin? The way he honoured Kor Phaeron? No, no and no. No mercy for Angron. Angron the Oathbreaker. Angron the Betrayer," -Angron
"Discipline leads to Victory It is Victory in War that brings Immortality Immortality is the Gift of Chaos In exchange, Chaos demands Blood Thus, Blood must be ever spilt Therefore, Eternal Life demands Eternal War Eternal War demands Eternal Discipline Chaos will always have Blood! Yours or Theirs!"