Brutus is, at various times, spoiled, a drunkard, and cowardly, yet gets a crowning moment of awesome just before his death at the battle of Philippi, which is clearly lost: he thanks his men for their service, kisses the signet ring made from the crown of the Tarquin King his ancestor drove from Rome, and walks off alone and unarmoured to fight an entire regiment of Octavian and Antony's soldiers, knowing full well he'll die in the attempt.
Titus Pullo gets far more than his fair share of awesome. However, probably the most spectacular moment came when a rival mob boss tries to defuse an armed confrontation by suggesting they talk things over like reasonable men. Pullo bites out his tongue.
CMOH's contain violence about 50% of the times if coming from the Antiquity (if it's described anything like accurately).
And don't forget Servillia. After the death of her son, she parks herself outside Atia's house and calls out "Atia of the Julii, I call for justice" over and over and freaking over again while her servant pours ashes over her. After what seems to be at least twelve solid hours of this, Atia finally has had enough and goes outside, and Servillia has the following to say: "Gods below: I am Servilia of the most ancient and sacred Junii of whose bones the seven hills of Rome are built. I summon you to listen. Curse this woman! Send her bitterness and despair for all of her life. Let her taste nothing but ashes and iron. Gods of the underworld, all that I have left I give to you in sacrifice if you will make it so." Then she stabs herself in the heart, followed by her servant doing the same. Antony's reaction: "Now that is an exit."
Guess they didn't listen though.
Oh no, they did. Atia spends the rest of the series being hounded to the point where she is a perfect painted mother to the perfect painted son who murdered the love of her life, knowing full well it was her love for power that caused all of it.
Octavian in Season 2, after suffering being everyone's Butt Monkey since he was a child, tells his family and Marc Antony they will do things his way from now on or suffer. Marc Antony tries calling his bluff and invites him to say how he intends to make him do anything, and Octavian renders him speechless and impotent with rage with an epic verbal beatdown, describing how he will destroy Marc Antony's power base (the respect of the Roman citizens and the armies), leading Marc Antony to raise his hand to Octavian and having the following sentence whispered into his ear to make him back down:
Octavian: Go on, strike me. See what happens.
It's even more epic when you consider Marc Antony's psychology: his whole life has been about fighting and physical prowess. He's been outfought physically, he's been beaten on the battlefield, but to be dominated by someone without a single blow being struck is more humiliating and infuriating for him than any lost war or personal defeat could ever be.
It's also a great call-back to when Antony beat Octavian up earlier in the story - you clearly see Octavian's calm and absolute triumph, repaying his shame and humiliation tenfold and knowing that Antony can never hurt him again.
Probably grating, but Lucius Vorenus also deserves one after taking over the Aventine collegia of Erastes Fulmen (as mentioned, a predecessor to the Italian mafia). Having gone from being an honorable centurion, to magistrate, and the first Plebeian senator, his "honorable background" makes the other "collegians" disdain his call to unite their forces. The proceedings were watched by priests of the goddess Concordia/Concord. Desirous to make an impression that he is now "bad to the bone" with enough "street cred," Vorenus calmly takes the image of Concord and smashes it on the wall, followed by this gem:
No less Awesome Vorenius' actual killing of Fulman. The Mob Boss is relaxing in a steam room when he hears the sound of fighting in the adjoining part of the tavern. After repeatedly shouting at his men to throw who ever is making the racket out a blood drenched Vorenius walks in. Fulman tries to run away to his men only to find that every single member of his crew has been slaughtered by Lucius and Pullo.
Fulman refusing to beg for his life in the face of this slaughter is pretty awesome in itself.
Atia giving Livia a perfect verbal smackdown with enough venom in the eyes and steel in the voice to make it really hurt. “I know who you are. I can see you. You're swearing now that, someday, you'll destroy me. Remember that far better women than you have sworn to do the same. Go look for them now.” The best bit? You know that she is in a pretty long spell of self-loathing and self-revelation, and she is the most vulnerable she's ever been. And yet she still bluffs her way to the front of her son's victory parade ahead of his wife.
It's also a backhanded, posthumous compliment to Servilia. Atia basically acknowledged the woman as her Worthy Opponent, and Livia was never going to match up.
Clerk (holding up a scroll for all to see): These being the words of Marcus Tullius Cicero... "I address you directly, Antony. Please listen as if you... as if you..."
Antony: Go on...
Clerk (shaken): "...please listen, as if you were sober and intelligent, and not a drink-sodden, sex-addled wreck." [Senators start fleeing the hall]
Clerk: "You are certainly not without accomplishments: it is a rare man who can boast of becoming a bankrupt before even coming of age. You have brought upon us war, pestilence and destruction. You are Rome's Helen of Troy. But then... but then..."
Antony (fuming): Go on... GO ON!
Clerk: "...a woman's role has always suited you best." [[Antony grabs the scroll and beats the clerk to death with it]]
Cicero was not, in real life or in the show, a particularly brave man. His actor can portray the pants soiling terror of death in Cicero's last moments, but you can see his deliberate refusal to cave in to his fear. It's brilliant.
After Caesar's assassination, Quintus Pompey tries to murder Marc Antony on the steps of the Senate. Antony barely escapes with his life, but surprises everyone by forming an alliance with Brutus instead of fleeing the city. The two embrace in public to show they're now friends, then a smiling Antony walks over to a puzzled Quintus as if he's going to embrace him as well...and slashes his throat. Then Antony casually strolls off while Quintus' men, because of the truce, just stand there gaping.