Imperial Knight Paladin: I have come to set this realm to order!
Taldeer: Taldeer serves you, as fate decrees.
Ronahn: A subtle hand shall turn the tide!
Macha: Fate has carried me to the field!
Solaria's reply to the Inquisitor demanding her assistance on Acheron. She reminds him already that he refused aid to House Varlock when she needed it, so she has no intent to help him. The Inquisitor points out how dangerous disobeying someone of his position is, but Solaria reminds him that he's been disgraced with the failure of his plan and when his superiors learn of it he will have no power. She calls the bluff of an inquisitor, and got away with it. The Inquisitor only convinces her to help with promise of recusing Gabriel Angelos.
Almost anything Gabriel does. He was badass in the original Dawn of War, but he really shows his chops here.
After fighting to stop the Orks and Eldar from the Vault and a rescue comes at the last minute, he barely has enough time for his men to escape for the Inquistor's orbital bombardment comes down and order them to go without him. And he survives, and on his own, continues to fight to keep the Orks and Eldar from the Spear of Khaine until he's mobbed by Howling Banshees and Wraithgaurd, which would have killed him if not for Solaria intervening with her knight.
Starting a Waaagh as the Orks causes the Waaagh tower to start playingheavy rock music, building to a peak before buffing all your surrounding troops so they're ready to charge in and overwhelm any enemy unfortunate enough to be in the way.
WAAAAGH! tower:Get ready boys! Deze boyz wanna rock. We boyz is made for rockin'. I CAN'T HEAR YOOUUUZ!. IZ YOUR READY!? FOR. A. WAAAAAAGH!!
As always, the faction superweapons, with the Space Marines summoning a lance strike from orbit, the Eldar a destructive psychic tempest, and the Orks bringing down a hail of asteroids.
The Announcement trailer, where after the end of THQ, many feared the state of the series. The trailer lessened those fears and made it clear that the series is coming back in the most awesome way possible.