I hope somebody has already mentioned this classic: The Emperor orders you to die! (for Space Marines obviously) This line is from the classic 40k game Chaos Gate and has been quoted frequently since. In the game it is one of the lines a Space Marine says before he fires his bolter at an enemy.
An Interrogator Chaplain, Is a Dark Angels Chaplain who specializes in Interrogating the fallen, making them repent and granting them death which then earns them a black pearl one famous one is Interrogator-Chaplain Asmodai
And every DA member that knows about the Fallen is a member of the inner circle ..regardless os skill or ability.
"Carpe Noctum" was the name of a Night Lords landraider, it means "Seize the Night" and could equally serve as a war cry
I made these up: For the Dark Angels I forgive thee not! I am The Blade of Caliban! I am the sword of the Lion! The Lions judgement is upon you! Onward the 1st Legion Forward the Lions Cause! I hear the Lions Call! 1st Amongst equals The Lions Wrath is upon you! Fear the Lions Roar! Enter the Lions Judgement! Now is the hour of Repentance! For Space Marines Fear my wrath Taste the fruits of thine treachery, heretic! Hear the Roar of my Boltgun, it is time to die! Ready your battle gear my brethren The Emperor Knows of your transgression Fear my Boltgun, face my wrath, vengance is at hand I stand on the shoulders of giants Your death is certain, my victory glorius The Emperors blood is in my veins Honour the victorius dead/the blood of martyrs Faith in the Emperor is my shield. Stars above stars below, all is the Emperors dominion! This is the emperors domain Ready your bolters With me Brothers This is the Emperors Jurisdiction Strike Cold and Fast Traitors and Heretics be ware Fear not the alien, the mutant, the heretic! There is only one answer to treachery! (cocks boltgun) Your death will be swift Die Son of Treachery For Blood Angels Be Sanguine brothers Noble Sons of Sangiunus, Forward! We are the Angels of Death I thirst for your Blood Remember the Blood of Martyrs In the confusion of the Black Rage: Horus you were my brother? Die Horus! AAAAAAAAHHHHHHHHHHHHH!
Loyalist Space Marines Death to the defilers of the land. Brothers! Enlighten these fools. Illuminate the xenos scum. Glory to the Imperium! This war is over, heretics! Come! And be cleansed with fire!
I'll do some more loyalists later. Felt like some DA love seeings they were my first 40K army. Dark Angels I am the angel of divine retribution ! The Lion still watches, do not falter ! Death and ruin shall be your penance. Knights of the Emperor, hold your ground ! For your sins there can be no redemption. Dark Angels ! Never abide, never relent ! Sons of the Lion, let the grief of Caliban gird your resolve ! Our vigil unending ! Our vengeance undimmed ! Retreat is no salvation, hunt them all down ! I am the shield of deliverance, the hammer of wrath. We are the first sword of the holy Emperor ! The path to absolution is paved with the unclean dead.