Anytime you use a Fat Man and watch the glorious explosion afterwards. Especially if your first time is the Super Mutant Behemoth attack in the Galaxy News Radio station, with the Brotherhood's best watching you in awe as you, a random wastelander, blows the giant to kingdom come.
And the MIRV is a Fat Man in shotgun mode.
The Experimental MIRV classes as a Gun of Awesome. No matter what you decide to use it on, it always leaves your mouth watering.
As the name implies, testing the weapon in different situations in the game and launching or even glitching your own character by firing into the ground turns The Experimental MIRV into its very own Sidetracked by the Gold Saucer.
Everything and anything with Liberty Prime in it, especially the first time you see it. They tell you that you and your allies will be leading the assault and the robot will be sent as back-up. Nuh-huh, the robot is leading the assault and your job is to find a good spot from which to view the epic Curb-Stomp Battle. Nothing stands in his way, or at least it doesn't stand for long before he blows it up.
Probability of mission hindrance : ZERO PERCENT! Battle analysis: Red Chinese Victory IMPOSSIBLE! Democracy is NON negotiable! Embrace democracy, OR YOU WILL BE ERADICATED!
Consider how long it took you to cover that kind of distance in the Capital proper earlier in the game, and behold how Liberty Prime strides unchecked through the heart of the city, straight up to the purifier complex, plowing through dozens of Enclave troopers like he was walking across the street for a loaf of bread.
Paradise Falls is widely regarded as one of the best gunfights in the game.
Three Dog's willingness to talk shit about you if you're an Evil character. You could easily show up and take him out without much effort, but he doesn't care, he sticks to his guns about bringing people the truth no matter how bad it hurts.
Any video where "the annoying man" gets executed is both awesome and hilarous at the same time. And even though you agreed to escort him, you don't lose any karma at all if you kill him!
Fawkes in general. Not only was he planning on breaking you out of the Enclave base with a Gatling Laser he apparently got hold of in a few hours for that express purpose, but he's also capable of taking down nearly anything on his own.
At the end of the Broken Steel quest "Who Dares Wins", you get to launch an orbital strike on the Enclave's airforce base! This is, of course, after you fight your way through the entire base full of Enclave troops. The most satisfying moment is when you realize just how royally screwed they are now after causing you and the wasteland so much trouble.
Managing to find and put together all the junk you need to create all of the makeshift weapons like the bottle cap mine or deathclaw gauntlet, then testing them all out on a group of raiders or other annoying foe. Nothing beats killing Demonic Spiders with the random trash you find lying around the wasteland.
Particularly so for the Rock-It Launcher. Is there anything more rewarding than slaughtering your foes with the cuddly wuddly death of a thousand teddies?
The finale of the Mothership Zeta DLC, where you engage in a space battle with another alien ship, especially when Sally treats it as if it were the climatic finale of an epic sci-fi TV series/movie/videogame.
Going to Old Olney armed with nothing but a Dart Gun, a Chinese Pistol, and a huge stockpile of 10mm ammo, and proceeding to Cherry Tap the Deathclaws into oblivion.
The hammy 'Adventures of Herbert "Daring" Dashwood' radio show. Particularly the one in which Argyle puts an end to the leader of the slavers:
Penelope Chase: Just ease away, zombie. No funny business...
Argyle: Funny business? Miss Chase, you hurt my feelings. I mean, there ain't nothin' funny about... THE EAGLE CLAW!
There's something poetic about taking out Enclave soldiers, equipped with the highest level of technology, with jury-rigged Wasteland weapons like the Rock-It Launcher, the Shiskebab, or the Nuka-Grenade. Imagine a soldier dragging himself back to Col. Autumn, having to explain that his squad just got annihilated by a can of soda and a high velocity teddy bear.
Assuming they survive the can of soda. Seriously, the blast on that thing is rivaled only by the mini-nuke.
Killing Mr. Burke before he can shoot Sheriff Simms in the back.
Dogmeat with the Broken Steel DLC is just amazing. Due to a glitch involved with leveling up, he has his health rise exponentially every time you gain a level. Assuming you found him early in the game, this means you can send him up against a veritable Supermutant Army on his own, and watch him come out with nary a scratch. At level five. Add on the Puppies! perk, which allows Dogmeat to respawn as a younger version of himself outside Vault 101, and you have a companion to be reckoned with.
If you get the Point Lookout DLC, you can get the quest to destroy the book in the Dunwich Building and you do so. After some Fridge Brilliance and a little thinking, it hits you. You just destroyed the Necronomicon. You did what thousands of Call of Cthulhu investigators failed to do.
Watching James punch out Deathclaws with his bare hands.
Or if he decides to skip over all the assault rifles dropped by raiders and instead pick up a sledgehammer.
Near the end of Broken Steel, you use the train in the Presidential Metro to get to Adams Air Force Base. After trekking through every subway system in the Capital Wasteland only to find out that the War did them in and rendered every train line unusable... and after using a handcart to travel to the Pitt... it's a refreshingly breathtaking moment from all the ruins you've seen everywhere in the wastes to have a fully functional train to ride in 200 years after an apocalyptic war.
Completing the quest "Stealing Independence." Having fought your way through the hordes of Super Mutants in order to save the Declaration of Independence, you may come to the conclusion that this really is much more than just a piece of paper. Thousands, nay millions, have fought for the ideals it stands for. You are now one of those proud few.
There's more. It's not just the Declaration of Independence you can get. You can also find the Bill of Rights. Even in a Crapsack World with no established system of law and order or any official human rights watch, you can still feel great not only taking two important documents of American history, but still cling onto the belief that everyone has the right to know that these actually existed.
Burke's an asshole, sure, but when Roy Phillips tries threatening him after his successful clearing out of Tenpenny Towers, he threatens Burke with the same fate as everybody else... but Burke merely threatens him back, and Roy starts back-pedalling and offering to make him his Number Two.
Towards the end of Mothership Zeta, by going off the beaten path, you'll find Toshiro, the Samurai you freed from cryostasis, surrounded by dead aliens. Then during the finale, Sally lets him into the control room where he proceeds to annihilate every wave of Aliens who storm in soon after.
Even better, if you help him along with the cowboy and the pre-War soldier. Think about it: The samurai, the cowboy, the pre-War soldier and you represent different periods of human history, and you are all destroying the alien invaders as payback for the centuries of abductions. You're all sending the aliens a message, and the message is "Humans Are Warriors". Showcased beautifully with the name of the last mission: The Galaxy Ain't Big Enough...
Hell, playing the game for the first time and hearing the menu music is a CMOA itself. It leaves quite an impression.
It gets even better. After (presumably) dealing with his arrogant attitude for a while, you have the honor of witnessing Braun having a Villainous Breakdown and yelling at you for ruining his fantasy world, while you can gloat right back at him and escape without repercussions.
Face it, the moment you step outside of the Vault for the first time is a personal CMoA after slaughtering most of the Vault 101 guards trying to get you.
Try not to smirk when you put a bullet into the last raider in Raider Base. Of course, then you will have to think about what to do with all those shiny things you have just found...
The fact that you can shoot weapons out of people's hands, and if you're quick enough, run up and steal it from them. Imagine facing down a Super Mutant Overlord and his unfairly-balanced-against-you-specifically Tri-Beam Laser Rifle, then shooting it out of his hands, grabbing it, and proceeding to blow his head off with his own gun.
Speaking of which, if an enemy is using grenades, you can use V.A.T.S to shoot the grenade while it's still in their hands and it will explode on your foe, along with any of their unlucky friends who happen to be close by.
One-shotting a behemoth with The Terrible Shotgun.
The fact that starting from this game onwards, no bad guy is a Karma Houdini if you wish it not to be. You can simply walk up to anybody you feel would be better off dead, and putting a round into their skull yourself. For example: Roy Philips. He kills everyone in Tenpenny tower about a week after his lot move in For the Evulz. And there is nothing barring the Karma Meter (and only if you don't want to take this risk and Pay Evil unto Evil) stopping you from going right into the tower and taking the sick fucker's head off in retribution.
After locking an exploding slaver collar on an NPC player tells NPC that they need to go to Paradise Falls or it will explode. The NPC replies: "Where's Paradise Falls?" and runs off in the WRONG direction.
Fred Wilks. His son, Brian, runs up to you and breathlessly rambles on about "those THINGS!", meaning the giant fire-breathing ants that have overtaken Grayditch. You find Fred lying dead in the living room of his home in the first leg of the quest arc, his corpse unarmed and clad in only his brahmin-skin wastelander outfit...and surrounded by dead fire ants. At the level you probably got this quest on, these bastards will be among the first Demonic Spiders you encounter. They're tough against most anything you might've gotten your hands on by that point in the game, and their fire breath will burn through your health very quickly if you let them get close to you. Fred Wilks held them off in his living room to give his kid a chance to escape, and managed to kill four of them with his bare hands before he expired.
As much as it's a Tear Jerker and Darkest Hour of the story, one cannot help but admire calm and collected Madison Li completely losing her shit and yelling into the Citadel gate intercom, voice audibly shaking with desperate anger, when the Brotherhood gate guard tries to turn her away after she just watched her closest friend get killed by the Enclave and she decides she will have none of that bullshit. And the best part is that it fucking works!
"LYONS! I KNOW YOU'RE IN THERE, I KNOW YOU CAN HEAR ME! YOU OPEN THIS GODDAMN DOOR RIGHT NOW!!!" (gate opens immediately)
Sure, you could walk into Raven Rock fully armed and just shoot everybody, loot their corpses and whistle a jaunty tune the whole damned time. Or, you could blow the whole damned mountain to hell, killing every Enclave mook inside all at once, and get the freaking President himself to kill himself — with your fucking words. Yes, you can Logic Bomb the freaking United States government to death.
