As JesuOtaku put it. "I can feel my soul dying and it is awesome!"
Seras Victoria's gaining a few levels in badass when she, blinded, maimed, and mindraped by Zorin, finally took the freely offered blood (and soul) of a mortally wounded Pip. Her eyes grew back, a mass of shadow emerged from the stump of her missing arm, and she proceeded to tear through the SS vampires that had overrun Hellsing manor before taking Zorin and literally grinding her head against the wall until it was gone.
He even gets one after that when Seras is fighting the werewolf. Nothing can stop Pip from being badass, not even death
Even his cameo in the epilogue is awesome. A nameless Iscariot mook informs his superiors about Hellsing's weak defenses and nil security system. A wall is punched and suddenly the entire walls and ceiling are covered in shadows. The masculine voice complains about how that 'hurt'. Pip, called as Seras' Shadow, is said to be wrapping the entire headquarters. Who needs another security system and killable guards when you have Pip Bernadotte?
And remember, aside from the last point, Pip and his soldiers are all ordinary humans.
Only a paragraph during Alucard's Flashback, but his statement that Abraham Van Hellsing was the only one who managed to take him down when he went all out and was (one of) the reason(s) he firmly believed only a human could destroy a monster like him. That alone put the founder of Hellsing as the single, most badass being in the entire Hellsing-verse. That he was only a doctor was the icing on the cake.
From the beginning of the second OVA, which actually shows the aftermath of that battle:
Abraham Van Hellsing: All flesh is grass, and all the comeliness thereof as the flower of the field. The grass withereth, the flower fadeth, but the word of our God abideth forever. *stakes Dracula* Dracula: Have I been... bested, sir? Van Hellsing: Yes, you are bested. This is not a nightmare you will be awaking from; your castles are plundered, you dominions in ruin, your servants destroyed, and the girl has fled this place forever more. She will never be yours, Count!" *raises his fist before bringing it down on the blunt end of the stake, hammering the sharp en even further into Dracula's body* "You are judged, and found wanting, Vampire King. You have nothing, you are nothing. Nothing!
The fourth OVA, where Alucard engages in battle with a warship filled with vampire Nazis by flying an SR-71 Blackbird into it. At almost Mach 3 (the exact speed is Mach 2.8). While perched on its nose.
And then he literally bites the bullet and, while he has the bullet between his teeth, grins sadistically and says to Rip Van Winkle: Guess what I just caught.
There's also his famous line... "If I'm a dog... Then you're dog food!"
"You were a piece of shit as a man. Now, you can be dog shit."
Alucard's rant at Luke Valentine: "What's the matter? You're only missing your legs. Come on. Call out your familiar! Transform your body! Regenerate your legs and stand! Pick up your gun and fight back! Come, the night's still young. The game's just beginning. Hurry, hurry, hurry, hurry, hurry, hurry, HURRY!"
Another great Alucard line is probably the following: (While fighting the anime's Big Bad) "I'll send you to the deepest pits of Hell, and while you're there, you can lick the Devil's ass, Incognito!"
Count Penwood, the commander of London security, gets one in the fifth episode of the OVA, when he admits being a "coward" and only getting this job because of his birth rather than any abilities, then staying in the HQ to face an army of vampires. He even tries to shoo out the rest of the officer staff to safety, which they obviously refuse, making this a Crowning Moment of Heartwarming, as well.
Just as epic is his final words. After being shot in the chest and both shoulders, he lifts up the detonator and glares at the vampire screaming at him not to blow the place up: "I. Will. Not. Stop." Cue Flashback Cut just before the Bang Bang BANG of enough plastic explosives to ensure everything in the building is Deader than Dead.
"Listen, to all humans who are receiving my final broadcast, this is my final order: Fight... until you've fulfilled your mission."
Doubles somewhat as a Funny Moment since Integra is standing right on the sidelines during the whole speech with nothing more than an annoyed look on her face. She doesn't even bother to react to the shots that almost hit her.
After many long scenes of horrific slaughter, it's incredibly satisfying to see the Nazi vampires getting mowed down by someone, anyone who's not going to kill the innocent people of London. Anderson and his Iscariot protégés literally destroy every vampire in the vicinity, showing just how well-trained and capable they are, especially Heinkel and Yumie. Anderson's Rousing Speech to his students is equally refreshing since it shows that he's just as disgusted by the senseless genocide as Integra is, and he refuses to stand by and allow it to continue. Not even Maxwell's orders are enough to trump his moral compass on the matter.
Seras Victoria using an 88mm Flak Cannon to try and kill the Major. Damn. In his words, a "Fantastic Choice!"
Seras performing her best impersonation of a AAA battery with a pair of 30 mm cannons stated to weigh over 700 pounds.
The original animated series had another one for Alexander Anderson, in the episode "Duel." A vampire starts walking up a subway car, with a bunch of ghouls in tow. He steps through a door, screams, and then falls to the ground with a dozen bayonets in his face. Anderson steps into the subway car, grins, and begins flinging bayonets, while quoting the Bible in his amazingly awesome voice:
"And now, O Kings, be ye wise. Be admonished, ye judges of the earth! Serve the LORD with fear, and rejoice with trembling! Kiss the Son, lest he be angry, and ye perish in the way, though his wrath be swiftly kindled. AMEN."
Anderson gets a great big CMOA all to himself upon Alucard's return to London. His final stand against Alucard has him battle valiantly against Alucard in Release State 0, tear through swathes of the undead army just to get to Alucard while almost being killed in the process, then sacrificing his own life to become what is essentially a monster born of God's powers. Even his death is a CMOA: Alucard shows him genuine respect for his total determination, even if he did turn himself into a monster.
The entire fight between Alucard and Alexander Anderson is perhaps the pinnacle of awesome for the series. The battle between the two most powerful characters in the series going full force at each other. From Alucard unleashing Level Zero on Anderson, to Anderson's refusal to give up even after the odds are stacked against him. Their next confrontation is no less great, with God Monster Anderson coming closer than anyone to actually killing Alucard. If not for a last second helping from Seras towards Alucard's infuriated counterattack, it's possible that Anderson may have prevailed where no other person, human or vampire, had succeeded before. It ultimately ends with both opponents showing mutual respect and understanding towards each other, and Alucard giving Anderson a genuine smileand a final "amen" as a sign of absolute respect for his greatest rival. A moment of awesome, tear-jerking, and heartwarming all rolled into one.
Integra, telling a group of evil Nazi vampires to not underestimate humans. And to come at her. So that she can fight them. She even impresses Anderson.
Additionally, the scene pretty soon afterwards when Integra enlists Anderson and a group of Icariot members as her personal escorts through sheer force of will.
And Integra, upset and furious after watching Alucard vanish, removes her coat and duels the Major in a Shut Up, Hannibal! way. She unflinchingly takes a grazing shot and kills the man with a single bullet and proceeds to tell him that all his ideas are warped and wrong. That Alucard "will return!" She was right
At the end of the second episode of the OVA, Jan Valentine manages to finally make hs way past what's left of Hellsing security, and bursts into the conference room of the Convention of Twelve. Who are all armed to the teeth and aiming their guns right at him, with Integra smirking. Jan manages to get off a single expletive before the Convention perforates him. Awesome.
"You made it! Congratulations."
Though retooled, the same scene in the original anime was pretty awesome as well. When Jan makes it to Integra, she quickly pulls her pistol on him and at point blank range shoots a perfect cross of bullets into his face which after a delay all start to burn.
In the TV series, Seras does battle with a wolf/vamp hybrid creature in the final episodes. She kills him by shoving a special grenade in his mouth. And her quote while the monster's choking on the bomb.
Seras: "...And on your way to hell...I want you to BEG for forgiveness for what you have done."
Integra gets a large number of awesome lines throughout the Hellsing's various iterations. Not the least awesome of which comes from the TV Series:
Integra: "These monsters dare to enter this house built on blood and honor! I will see them all roast in the deepest pits of Hell!"
In Episode 10, how she fearlessly tells Alucard off.
Episode 3 of the OVA had a particularly awesome moment when Alucard calls Integra after slaughtering a SWAT Team sent up to the penthouse. Asking for his commands, Integra takes a moment and lights a cigar then in the most Hamtastic way possible retells him his commands.
Integra: DON'T YOU DARE QUESTION MY RESOLVE, I'VE ALREADY GIVEN YOU YOUR MARCHING ORDERS, SOLDIER! YOU WILL SEARCH AND DESTROY! SEARCH! AND! DESTROY! ANY RESISTANCE IS TO BE CRUSHED! HELLSING DOES NOT RUN FROM THEIR ENEMIES, KILL THEM ALL! I ORDER YOU TO LEAVE NOTHING BUT BLOODY STAINS IN YOUR WAKE!
A similar scene from OVA 8 during the Vatican Invasion of London. Though, it is far less hammy.
Integra: Alucard, take heed. Here are your orders. Your silver gun will stain the white army crimson. Your iron gun will stain the black army scarlet. I would know my foes by the stains of red you leave upon their chests! Now search and destroy! SEARCH AND DESTROY! RUN THEM DOWN! DO NOT LET ANY OF THEM LEAVE THE ISLAND ALIVE!
OVA 9 gives her most utterly bombastic delivery of the series, and while it is magnificent, it becomes clear she is purposely pushing herself as hard as she can, like it's the only way she can keep going. It still doesn't quite keep her from breaking down. She lights a cigar, takes a long puff, then snaps it between her fingers, and then...
Integra: SEARCH AND DESTROY! Search and destroy! Servant! I have given my order! It has not changed! We crush all those who oppose us! We grind all who stand in our way into dust! No matter who they are! No matter WHAT they are! No matter...no matter who they are...
Let's be honest, Alucard gets far more opportunities to show off how very hard core he is — but the Major dismisses Zorin's claims that Integra and Seras will be easy prey, by saying that he considers them to be on the same level as Alucard. That is how badass the two leading ladies are.
Alucard himself believed so, just seconds before they started taking the Zeppelin down together while he fought Walter.
From OVA 8, the whole scene with the Major conducting the war looked awesome. He was just going through all the gestures like he was literally making a symphony, ignored Doc completely, and didn't even flinch when a helicopter came to shoot him down. He already knew that Walter was going to help him out. It was definitely impressive to watch.
The Major's flashback in OVA X provides a truly awesome one. It shows him as a Nazi officer fighting in Berlin during the Russian invasion 1945 and surrounded by a Soviet fireteam; the Russian soldiers knock him to the ground and beat him, and one shoots him several times in the chest as the group walks away. After they leave, a pool of blood starts flowing towards the Major as he struggles to pick himself up. He looks at it and sees that this is the work of a dark force offering him the chance to become an immortal monster of carnage. And how does he respond? With one word: Begone. It's his life and soul being bargained for, and nothing in this world can convince him to give them up. As the wave of blood splashes back, unable to reach the Major, you can't help but admit that for all his depravity, the Major values his humanity more than almost anyone else in the series, enough to reject the scepter of unholy power where supposedly nobler warriors like Alucard and Anderson willfully took it, and as the Major smiles while watching Doc rush in to save him, you can forget everything else about him for a brief moment and share in his personal victory; the triumph of the human spirit over the temptations of monstrous power.
OVA 10: Seras and Pip vs. the Captain. Not only does Seras defeat an opponent that Alucard and Walter were forced to retreat from, but the Captain himself proves his Badass credentials by utterly dominating their fight until he equips her with the means to kill him.