All of the characters seem to be getting theirs one by one (some of the main ones several). Here's what we got so far.
Maka & Soul
The first episode has, by far the coolest line in anime during the "fight" between Maka and Soul.
Maka: Then why do men cheat?!
Soul: How should I know? Cool guys don't cheat.
Soul saving Maka from a lethal blow by taking it himself...and surviving, albeit barely. Later, he snaps viciously at the little demon inside his soul, making the usually dominant bugger back off momentarily before trying another tactic.
When Maka willingly makes herself go insane in order to beat Crona into submission, she stops Crona's sword with her arm, then proceeds to grin maliciously and then swing Soul (in scythe form) around to send her opponent flying. She continues to whale on her opponent despite getting injured.
Hell, even before that when the fight starts and Maka remembers that slicing him won't work due to the black blood. Her response? JUST FUCKING PUNCH HIM. For about two minutes, she does NOTHING but just beat the everliving snot out of the guy with her fists and feet, and IT IS AWESOME.
Episode 24/chapter 22 when the Kishin busts through the roof, Maka comes speeding in at the last second and grabs on to one of the kishin's...trailing skin...while using scythe soul to atempt to slow him down, refusing to let go even when rocks from the tunnel shower down on her, all the way to the surface.
During the anime, when they go to rescue Crona and Stien, Medusa gets Maka pissed. When Maka gets ready to attack, Medusa claims she can't hurt her because of the deal with the academy. Maka's response?
Maka:"I DON'T GIVE A DAMN!
Maka and Soul perform a double-whammy of awesome in chapter 59 As Arachane spreads her insanity wavelength across the battlefield Soul figures out how to use her own trick against her by using her network of webs to deliver Maka's anti-demon wavelength to the fighters and Arachane forcing her to return to a physical body. Maka finishes the onslaught of awesome by resonating with Soul, saying her classic line: "I'll take your soul", while changing into a dress actually made of black blood, which adds to her defense, and is also the one she wore when she entered the Little Devil's Musical Room inside Soul's... soul. Finally, in the next chapter, when Arachne shouts that Maka is stupid for thinking courage alone will give her enough power to defeat her, Maka simply says "I'm stronger than you. Take that." and proceeds to cut her in half, thus owning a witch's soul
In the final episode of Soul Eater, (Anime Exclusive, so far) Maka snaps during the battle against the Kishin and her body takes over while she's unconscious...by using her Weapons blood. Maka sprouts and retracts awesome scythe-blades from various parts of the body and beats Kishin's face in until he realizes what's up and snaps her out of it.
Wait wait wait wait. You left out the best part. He "snaps her out of it" by plunging his hand dagger-style halfway into her chest. Maka comes to and lets out a ten-second long scream of pure agony! This is less a CMOA for Maka than it is for her voice actress.
Even better is when, at the end of the episode with a "Fist full of Courage" she runs up, past all of Kishin's attacks, only to Falcon Punch him in the face. He chuckles about how this did nothing, only for his ENTIRE HEAD to crack, before he explodes.
Soul, in an attempt to protect his meister from Giriko, and Maka's own Book-heightened apathy, fights the psychotic chainsaw on his own and...is not dead/incapacitated yet in ch75. Even when he gets cut across the chest again. Seems he's taken Maka's sense of courage to heart.
Black☆Star & Tsubaki
Tsubaki's crowning moment was when she managed to escape from being absorbed by her brother, only to absorb him.
Black☆Star: Take your pick. His battles with Mifune, the attacks on Asura, his fight with a madness possessed Death the Kid, etc.
Black☆Star has had several but a notable one is his reappearance. After being in Japan as a break to prevent himself from going down the same path as his father, he arrives at Arachne's lair in a fashion best suited to him; tearing down the thick forest with berserker speed (ignoring orders not to move in), tripping all the sensors used to detect enemies. This distracts all the guards, allowing his commrades to move forward. Not only that, but he begins to fight with Mifune for the third time, revealing several new forms of Tsubaki in katana mode. The second form (technically the third one) allows him to move fast enough that he leaves behind several afterimages with actual mass.
The end to that fight counts as one as well. When Mifune recognizes Black☆Star as a true warrior and drops his Flood Line skill so as to only use one sword against him. Black☆Star then tells Tsubaki to change the weight of the Uncanny Sword to that of a regular katana while getting rid of the shadow scarf to fight Mifune on equal ground. The fight result is a bloody and beautiful, and ends with Black☆Star slashing halfway through Mifune's chest and dying a true warrior's death.
Anime: Mifune slashes Black☆Star fatally. Scary thingies that are regretful warriors swallow him. He gets back up, in a golden beam of light no less, and in his Enchanted Sword realm, he does the most epic speech.
Black☆Star: I absolutely won't give up! When I lose is when I die! Until I myself accept that I've lost... then I haven't lost!
For me, it was when Black☆Star was able to snap Kid out of his Face Heel Turn and make it through all seven chapters of the Book of Eibon
Also Black☆Star vs Chrona total Curb-Stomp Battle even with the help of the Mizune sisters and Eruka lobbing bombs at them.
The most recent chapter has Black☆Star catching lasers with his bare hands, then throwing them back before pulling a Dynamic Entry on the clown army on the moon.
Chapter 108, He literally eats a Vajra blast and survives.
"I'm human! It doesn't mean I'm weaker than a god! Things aren't always as you think them to be!"
Death the Kid, Patty and Liz
I'm surprised his victory in his debut episode wasn't mentioned here yet! He completes his mission to destroy the cursed soul of a witch and kill a mummy who absorbed her by blasting it point blank with both his pistols in about a hundred shots, which eventually demolishes the entire pyramid... all because the mummy wasn't at all symmetrical!
And this is after he spent a few minutes letting it impale him multiple times and beat on him with a giant hammer, simply because it was symmetrical before it showed its real face.
The only thing that remained of the mummy? The little decoration on its forehead. In other words, the only thing about it that was symmetrical.
Defeating Black☆Star, who's considered the strongest fighter, without even needing his weapons.
Most recent one was when he was getting owned by Mosquito's revitalized form, only to suddenly awaken to an inner power thanks to BREW. He gets up and looks over at his currently missing arm. Suddenly, the arm starts reattaching itself, and then Kidd starts fighting on par with Mosquito. Not only that, but one of his white hairlines becomes symmetrical, revealing that his obsession with symmetry is actually plot-relevant.
That, and that he didn't care about the symmetry the line created. It's well known that Kid's obsession with symmetry has a pretty damn hard grip on him, so the fact that he simply brushed it aside just makes him that more awesome.
Liz: Wait... Kid... One of the lines on your hair...
Death the Kid: You don't have to tell me. In any other situation, I'd be obsessing over it about now.
I'm surprised that his stunt in episode 50 hasn't been mentioned. After being stabbed and apparently dead, he starts floating, all the lines in his hair connect, and Liz and Patty transform into GIANT cannons, blowing away the form the kishin gained from eating Arachne's soul. In one shot.
"I dreamed of a world where you did not exist. I'll enforce your death penalty, Noah."
And then he does. Parent's Seven Rays anyone?
Pretty much every time we're reminded that the quirky little guy is a god. An uncanny, unpredictable small god.
Kid gets taken to the witch's council to try and get them to help, it turns out to be a set up. Kid's Badass Boast that he could easily kill every witch at the council without any trouble is just nothing short of awesome. And this is without Liz and Patty, who were left behind at Shibusen.
Not just the Badass Boast, how well he handled that entire situation was awesome. The trial started with a mob of hostile witches dishing out million death sentences, but after a few pages of intimidation, proposal, confusing Kim joke and pleading, he walked out of the witch realm leaving behind a council of witches discussing Shibusen request seriously. I would call that a diplomatic CMOA.
Shinigami-sama in the old days, as well as his (short-lived) fight against the Kishin.
Doesn't even matter that he technically lost, that was a crowning moment of badass.
"You filthy unforgivable swine! That's it, I'M GOING TO SKIN YOU ALIVE AGAIN!"
Shinigami in Episode 47: Shinigami + All Demon Tools = Eye Poking Humongous Mecha
Shinigami Chopping Chibi Medusa
Even when he presumably reacted like that only because Medusa was in a child's body, there's still the sense he was saying she's nothing more to him than a naughty child who's made a mess of things. And then there's how Shinigami and Spirit treat her afterwards...
Whenever he talks in his deep voice.
Blair is when she takes on the rest of the Mizune sisters and manages to land several powerful blows in cat form. The sisters then form one more humanoid woman in a skimpy outfit. Blair transforms into her human form. The new Mizune gropes Blair, and in response, Blair lifts Mizune's shirt. A cat (ha!) fight soon ensues. The onlooking fish salesman almost passes out from sheer pleasure. Later, she then single-handedly, through sheer cunning and wit, made Nizuheg press his own self-destruct button, without once transforming into a human.
Baba Yaga's Castle Chapter 15, where it's revealed just how much she has been playing everyone, namely setting the whole thing up, actually kidnapping Crona herself, all so she can steal her sister's body and kill Maka while she's at it. She fails the last part of the plan but everyone thing else worked perfectly. It's like she's going for the record in sheer manipulative bastardry.
Ox broke (yes, broke) his hair in order to try and get Kim to come to her senses. While it seems silly, the moment is a mix of this and heartwarming.
Kilik, after waiting around in plain sight for a while, decides there's no point in trying to sneak past all the people guarding the tower he's aiming for, and so takes off his disguise. What does he say? "Surprise."
Mifune, in episode 28 during his second battle with Black☆Star. Pretty much the entire battle, and flashbacks. They even changed the opening theme to the song that debued in this battle, it was that hardcore. This leads up to further moments such as the later battle against Cid, his dagger, and a Death Blunderbuss.
Stein owns Black☆Star without getting up from his chair.
Kilik and Kim fighting the Black Clown. Especially considering that Kilik was teamed up with four weapons at once, when Kidd himself said that using two at once was incredibly difficult. And then he has them combine their powers into a Wave Motion Gun.
Stein and Spirit versus Medusa. In between the scientist and witch attacking each another, they chat about chaos, authority, and the entertaining prospects of hurting one another. While Spirit hangs around trying to keep an eye on Stein and they both restrain Medusa. The moment when Stein slices Medusa in two, and she 'wins' because it was Asura's freed soul that allowed him to do so is surely one of the most awesome events in the series. The anime makes it all the more so, thanks to the voice-actor's creepy, fantastic, laughter.
Stein: "Medusa, consider yourself fired."
I'm surprised Hiro hasn't been mentioned yet. Being the only one in the series who can deal with every one of Excalibur's provisions is awesome.
Harvar's moments of combat pragmatism in the Baba Yaga arc. He gets rid of the Artifact soldier distracting Thunder and Fire by slicing it in two (to their distress, they are little kids). He solves the threat of a still-brainwashed Jackie by knocking her out. His earlier stabbing of Kim to protect Ox is less-than awesome due to its brutality, but it showed a kind of sense. Plus, his all-round stoicism averts the usual Personality Powers of one with Shock and Awe abilities.
What makes all this better is that his personality was firmly established in the same chapter he stabbed Kim. The fact he was able to overpower and actually stab a meister wielding a weapon without the help of his meister actually makes that moment pretty awesome.
Come on. Who didn't cheer when Black Star punched Maka?
This troper actually doesn't mind Maka and finds Black Star to be the more annoying one.
"We were reckless". There's something awesome about the moment when, after opening episodes of crazy action and general light-hearted shounen-ness, Maka and Soul find themselves with no way out of the cathedral, or away from Crona (who kept telling them they were trapped) and just how far out of their depth they are. They didn't know what they were up against, and realising - along with the whole of Crona's debut - was the first indication of how the author likestoplay.
Crona and Ragnarok splitting the Nidhogg and the Flying Dutchman into two perfect halves. And this was right after the Flying Dutchman called them "rookies." Even Kid was amazed.
After faking his own death, Tezca Tlipoca demonstrates to Justin that he's not just tougher than he looks, he's nigh-indestructible. Cut his reflection-clones to pieces? They'll just make a new body.
In chapter 87, where Crona completely destroys Medusa, and calls her out for being a horrible mother. Like a boss, Crona. Like a BOSS.
Crona: I don't want to hear gentle words...they annoy me. I don't know how to deal with them. I threw everything away because you told me to. I THREW EVERYTHING AWAY BECAUSE YOU TOLD ME TO! But that's unfair, mother, because I threw away the only one who really loves me...if you threw everything away, does that mean you threw me away, too!?
The anime version of this too. Gecko Ending or not, it was awesome to finally see Medusa get what was coming to her.
Actually, this is a subversion. A good part of the awesome of Crona calling Medusa out and killing her dilutes when you realize that, well, it was ALL a part of Medusa's plan, and thus Medusa yet again has the upper hand over Crona, making them even more of a slave to her will than they ever were before. So the REAL CMOA goes to Medusa, for being smart and cruel enough to use her very own death to her biggest advantage and dominate Chrona for-e-ver, unless Maka and Soul can do something definitive to stop the death order coming from Shinigami - one that even Kid approves of. (Even if he doesn't seem to like it.)
For a short lived character, Feodor got one of the best. By simply kicking Chrona. In the face.
Asura's scream after being broken out of a sack made from his own skin was a comic CMoA. At the end of the anime his comment on bravery was badass.
Asura: Everybody has it? So, it's just like madness, then.
Spirit's Big Damn Heroes moment in chapter 106. Firstly, he protects Maka by blocking/damaging Crona's black blood on his own, then has Maka act as his meister, sure of the fact that Crona's madness cannot break the bond between parent and child. No mucking around, just calmly badass when the others were getting unnerved.