A really minor thing, but at the entrance to Quarry Junction, you find a dead Powder Ganger. He has a knife, the clothes on his back and some caps. Next to him are two dead young Deathclaws. He killed two young Deathclaws without any actual armor, using a knife. He must've been one tough son of a bitch.
Benny: "From where you're kneeling, it must seem like an 18 karat run of bad luck. Truth is... the game was rigged from the start."
This can be made more awesome when you finally track him down, steal the gun he used on you, and do exactly what he did to you. But this time the death part sticks.
In general, the way you can absolutely destroy the Legion's operations before even getting to Vegas. The Courier: Kills the head of the Frumentari and all his bodyguards, wipes out a small slaving camp, covers Cottonwood Cove in radioactive waste (killing everyone there and leaving it uninhabitable), kills various Legion patrols, leads a small NCR task force to kill everyone in Nelson, kills the Legion assassins sent after him/her (which can potentially be a lot of Elite Mooks), repels an attack on Bitter Springs, destroys the Fiends and kills all their leaders, gets the information from Silus, digs out the Legion spy at McCarran, and kills all the Recruit Legionaries stationed at the Techattiicup Mine. Then, after reaching Vegas, they can kill Alerio after he gives the Mark of Caesar, foil the Omertas' plot to attack the strip, sever their alliance with the Great Khans, upgrade the securitrons under the Fort, and, as a final nail in the coffin for their operations in the Mojave, the Courier can rampage through their main base, killing dozens of their best troops, until they finally kill Caesar himself. Who would've thought one person would pretty singlehandedly turn the tables on the second largest army in the post-war world?
First Sergeant Astor puts it best after you destroy Cottonwood Cove personally.
Astor: You're a beast, son.
Better yet, do all that with a female Courier. Astor will get a kick out of the delicious irony considering the Legion's brutal misogyny.
Do all of that, but hold off on killing Caesar until after you walk into his tent, and hear the Would-Be-God-King list off all the ways you have screwed him over, and then kill him.
Caesar: You're the courier who's caused so much trouble for my Legion, and yet you dare come before me. Vulpes Inculta, the best of my frumentarii, is dead. All the bribes I sent to the Omertas ended up buying me nothing. The Great Khans aren't exactly clamoring to fight for my Legion now. The garrison I established at Nelson has been wiped out. Years of meticulous scheming to place a mole at Camp McCarran - wasted. The Kings of Freeside are cooperating with the NCR now, which frees up soldiers to defend the dam. You even disrupted a promising weapons deal with the Van Graffs. So tell me this, because I really want to know: I am feared - with good reason - but you of all people dare to come before me, the mighty Caesar. What were you thinking?
Courier: Death to tyrants! <Start combat.>
Caesar: Praetorians! To arms!
To top it off, if you have Terrifying Presence, you can simply tell Caesar that you're going to decorate the interior of his tent with his own guts, and he flips out in sheer terror.
In the process, the Gun Runner's Arsenal DLC allows you to get a perk for reenacting his namesake's famous death: Kill him with a knife and earn the Historical Propriety challenge.
Lonesome Road takes it even farther, giving you the opportunity to nuke the Legion, including Dry Wells, the village of Ulysses's former tribe.
It takes a fair bit of effort, but - get every major unique weapon in the game. Equip them all (comes to about 215 pounds). Equip the Prototype stealth suit so you don't have to worry about health. Convince the Brotherhood, the Boomers and the Remnants to back the NCR in Hoover Dam, and then begin For the Republic. The Legion truly have no idea what they're dealing with.
The entirety of No Gods, No Masters.
The Second Battle of Hoover Dam is filled with these, and many of them are a direct result of the player's actions. This includes:
Getting the Boomers' help will have them rebuild the old bomber they had you recover and utterly decimate your enemy. They also provide fire support with their howitzers.
Forging an alliance with the Brotherhood of Steel and the NCR will supplement the NCR with fully armored Brotherhood Paladins that lay the beat down on the poor Legionaries.
Seeing the Enclave Remnants show up in a Vertibird and start disintegrating enemies left and right is always fun to watch.
If talked to during the battle, Cannibal Johnson gives these badass words.
Cannibal Johnson: Come on, kid, there are still bad guys to fight.
For context, this is after the Enclave Vertibird and its crew arrive. After this, you're being escorted by the beings that put the fear of god into every person west of the Colorado. After that day, every person east of the Colorado will be fearful of them too.
Also if you upgraded the Securitrons under the Fort and then used the Dam to power them up, you see Caesar's entire stronghold go up in flames in the distance.
Doing all of the above, and getting all the various factions to go along with your plans. There's nothing quite like watching the Brotherhood, NCR, what's left of the Enclave and the Boomers all fighting side by side, especially when you reach the top of the dam. Paladins supporting riflemen, and suddenly that B-29 bomber comes in low to drop fiery death. And then the vertibird, packed full of Badass Grandpas/Grandmas comes out of nowhere.
For Wild Card players, having Yes-Man help you take control of Hoover Dam, release the Securitron army under Caesar's Fort, and then storm the Legate's camp. You can either use superior logic to trick Lanius into retreating by telling him he cannot possibly hold the entire state of California, or by killing him, which results in a large fight with Lanius and multiple Legionaries trying to melee you to death. After dealing with the Legate, you run into General Oliver of the NCR, who gullibly believes you just came and took back the Dam for them. You then break it to him that there are literally hundreds of Securitrons flanking him from behind. He then begins to get arrogant and starts insulting you. You could make him leave peacefully... Or have Yes Man throw him off the Dam.
Interrogating Silus at Camp McCarran, if you have a high intelligence. You claim to be an assassin sent by Caesar to silence the centurion, and you can prove it to by him using your choice of Latin phrases.
Boone's one liner if you kill Caesar with him in your party. "Thumbs down, you son of a bitch."
This becomes ten times more awesome if Boone lands the killing blow. One hundreds times more awesome if Boone kills Caesar with a headshot. Take into consideration his dialogue line before reaching the Fort - about how he wants to put a hole in Caesar's head - and Boone becomes the Little Engine That Could.
Continuing the line of killing Caesar, there's always the option of single-handedly killing every Legionnaire in the camp, then instead of going with cloak and dagger-style assassination, just busting down his tent's door and unloading a mini-nukeright in his face. For bonus points, run out of his tent and send a nuke at his pursuing guards, then put away the Fatman, put on your sunglasses, and walk away in front of the explosion.
What's even better is completing the Honest Hearts questline (preferably the Good Karma way) and return to Caesar's camp wearing Joshua Graham's body armor and carrying his unique pistol.
The Gun Runners' Arsenal offers two different ways to kill Caesar and get rewarded with XP for it: Even A God-King Can Bleed, in which you spear the bastard in the head or Historical Propriety, in which you personally reenact the Ides of March and shank him to death. Best part? These aren't mutually exclusive. Do both while Boone headshots his Praetorian Guards.
"Thumbs down, you son of a bitch."
Though it's otherwise very tragic, Boone's bad ending in a Legion victory is a true Dying Moment of Awesome. Furious over the Legion's victory and driven by his memories of his wife, Boone stages a suicidal attack on them, "fighting as he wished he would've fought on the day of his wife's death," and he brings down scores of Legion officers before he's captured. Before he's crucified, Caesar comes to see him to express his admiration for Boone's reckless bravery. In response, before the entire Legion watching, Boone spits in his eye.
At one point, some NCR mercs will show up to harass quaint Jacobstown, and Marcus asks you to deal with them. Sure, you can bribe them or just kill them, but the most badass option? Talking it out. Why should they leave? Because instead of fighting an entire village of super mutants, they'll have to fight you. The entire company leaves right away.
Finding Benny in The Tops, getting attacked by his henchmen, slaughtering the four of them, and sending Benny, one of the most powerful people in New Vegas, running for the hills.
Benny: The cleaners will knock twice. Tell them to be thorough.
Option 1: Your little trap failed, Benny.
Option 2: It's a real mess up here... there's four bodies.
Alternately, convincing Benny to separate himself from his bodyguards.
And extra value points if you do it by appealing to his (ahem) little Caesar. Seriously, the very fact that seducing him and murdering him in his sleep is even in the game is amazing. Pulling it off makes your Courier the greatest seductress of Vegas.
While Terrifying Presence is useless if you're playing for keeps, if you're playing to have fun then it lets you be one mean son of a bitch. To the point that you can utterly terrifyVulpes upon meeting him in Nipton.
Courier: I'll wear your head like you wear that dog's.
Insert headshot before he can even ready his weapon.
If you own the Ultimate Edition, you'll have access to a few unique weapons from the start of the game, including the Weathered 10mm Pistol and the Mercenary's Grenade Rifle, a better version of the M79 quite a bit sooner before you'd normally encounter 40mm weapons (you'll also very likely have lots of dynamite from killing Powder Gangers prior to this). When you call Inculta out for comitting war crimes, he'll smugly reply that all crimes are unforgivable, and challenge you to do something about it if you feel so strongly about it, promising after that you won't feel anything ever again. He'll then calmly turn and walk away...if you let him. It's quite satisfying to blow his entire party away with a well placed grenade before they have a chance to react.
Fighting in the Legion Arena gives you one if you get to the final round, where you face off against a Ranger who's a genuine Action Girl. The fight tends to be visceral and brutal, and despite the immorality of the whole thing, sparks a certain savage enjoyment. Unless you're hugely overlevelled and curbstomp everything of course.
Terrifying Presence pulls so many of these off it's amazing, even if it's criminally underused.
If you tell Veronica to defect from the BOS and join the Followers, the Paladins that have been harassing you though her quest show up, murder the Followers doctors and try to pull one on you. What happens next is just pure awesome.
Paladin: "In the name of the Codex, I sentence you to death."
Paladin: <in a high pitch terrified voice> "No! No. NOOO!"
Using it to save Cass from Jean Baptiste.
The Courier: "You raise that gun and I will kill everyone in this room."
The Extra Mile: As soon as the dialogue window closes, whip out any of the unique revolvers ('Lucky', The Mysterious Magnum, or even the Ranger Sequoia), target every unfriendly skull in the room with VATS, and end the fight before it even begins.note (Using high Guns, high Base Agility, the Action Boy perk, and being high off your tits on Rocket)
Reclaiming Nelson from the Legion with Boone. Aside from the fact that the terrain around the camp is ideal for sniping, you get some dialogue from him that makes the mission feel as if it's gone from a request to Mercy Kill a bunch of NCR troopers to an all-out rescue mission that not only sees you saving those troopers, but also liberating the entire camp from Dead Sea.
After you pickpocket Cachino's journal out of his pocket, you can confront him and tell him he's going down. He'll offer you 100 caps for it, or 200 with a Barter check. However, passing the Barter check just gains him your friendship, not the journal. So yes, a sufficiently ambitious Courier can make him pay for his life twice.
The Courier has lots more chances of being witnessed performing unusual deeds than in previous games, making him a bit more believable as a great hero. One particular moment comes from retrieving a fallen Ranger's corpse, which was being used by Fiends to ambush other rangers and NCR soldiers. Literally carrying his body back to an NCR position has you stating a few things about yourself, and the soldiers there responding in actual awe:
Courier: I just did what anyone else would have done.
NCR Soldier: Bullshit! Anyone else would have gotten killed!
Or a little more boastful:
Courier: Now the Fiends and the NCR know not to fuck with me!
NCR soldier: No fucking kidding!
Or one that while modest, is no less badass:
Courier: I made a promise to Private Morales.
NCR Soldier: That must be some code of honor you hold yourself to. Don't worry, no need for you to hoist him over your shoulder and haul him all the way back to California, like I know you would if you had to.
There's also dialogue if you retrieve the body at full health and return without taking a single point of damage.
NCR Soldier: Oh my god. How the fuck did you do that!?!
Or you could play for the Legion and wipe out Camp Forlorn Hope all on your own. For the extra bit of satisfaction, do so as a sniper and kill the sniper-rifle wielding NCR elite rangers by sneak-headshot. You can also try and stay in stealth for the entire mission, picking off the high-ranking officers one by one in stealth with a few well-placed headshots. Even when there is only one of them left, they never saw it coming.
Speaking of stealth kills, anytime the player manages to complete a quest that requires them to kill faction members without any faction loss or just doing so for giggles counts. One way to do this is to kill these people with one shot while sneaking and without anybody else able to see you. This is especially fun during enclosed or heavily patrolled areas.
Picture it, the Powder Gangers are just sitting in their "biggest, baddest fort in the wasteland" when suddenly they start dropping like flies. Everybody is freaking out, trying to find where the shots are coming from. Before long everybody in the entire prison is dead, and "I Fought The Law" is completed.
Go to Helios One as a Legion-aligned player, restore power, arm the defence system, go outside, and just watch.
Operating on Caesar's brain tumour. Yep, the Courier's pretty awesome.
Bonus points if you have at least 20 medicine and only made it through because of that 9 in your luck stat.
You and Boone singlehandedly repelling the Legion raiding party during Boone's companion quest. Admittedly, it's not as big as Boone made it out to be (a dozen Prime Legionaries and six dogs), but it's still awesome. It's even better when you hear the news broadcast on the Mr.New Vegas show later. One of the refugees was quoted as saying: "God sent us two two angels for protection, and at least one of them had a .308 caliber flaming sword of justice with a telescopic sight."
Your introduction to the Legion at Nipton. Sure, it's horrifying, and shows just how ruthless and merciless they are, but it's one hell of a way to make a first impression.
Outside of Camp Searchlight are a group of NCR troopers who were on patrol when the Legion detonated a radioactive device in the city, turning nearly everyone to feral ghouls. By the time the game starts, the aforementioned NCR troopers are patrolling the perimeter of the irradiated city warning anyone about the radiation all while in danger of radiation poisoning themselves and attacks from feral ghouls.
If you have the Terrifying Presence perk, then during the Van Graff quest you can use it to make Jean Baptiste back off when he threatens to murder Cass. You make one of the game's biggest psychopaths back down using just a single threat.
If you take Arcade with you to the Fort to listen to Caesar's proposal, when the Legion's leader is done giving his Motive Rant, the normally calm and collected Arcade explodes, laying into Ceaser and outlining exactly why his "empire" is a sham and why his ambitions are doomed to fail. And it's glorious.
Additional awesome. The lines were original dummied out from the game, since you can't take companions into the tent. However after fans found out about the lines, the devs worked them back in via a patch, with Arcade now giving it after you left the tent.
The Evil Mr. House ending says that half the reason he lets you live in the lap of luxury at the Lucky 38 is because he's afraid of you. He controls an unstoppable robot army (which you gave him) and you still scare the crap out of him all by yourself.
A meta example. JE Sawyer released a mod that greatly corrects errors in the game, fixes DLC issues, made Hardcore Mode actually hardcore, made the rewards for Dead Money less game-breaking, and added Damage Resistance back to the game for certain armors. After the game had finished production and they weren't going to continue working on it officially. That's dedication to making sure it runs right.
This YouTube video has a playthrough that tries to end with diplomacy but ultimately fails due to a speech stat that's a bit too low. They then give Lanius the beating of a lifetime.
Bonus points if the Pulse Gun was one of the items used in Veronica's companion quest: when presented to the Elder, they will dismiss that the Pulse Gun could wipe out the entire Brotherhood, thinking that the one Veronica had was "the only one of its kind". Then, as you and Veronica leave Hidden Valley, a gang of Brotherhood Paladins hold you up at gunpoint, claiming you're spreading ideas contrary to the Brotherhood and the Codex, and that you should be sentenced to death for it. Assuming you don't waste the bastards then and there (although doing so will fail the quest, and cause Veronica to leave you in disgust), you can simply say Veroncia was leaving (which the Paladins smugly accept as exiling her), and then you can suggest that Veronica join a Followers outpost only for the Paladin gang to massacre everybody in the outpost out of spite, and then turn to kill you and Veronica when you show up. Thenyou can totally waste the bastards without any repercussions from either Veronica, or even the rest of the Brotherhood.
Once you've obtained the Gauss Rifle; put on some good armor, find a deathclaw, wait for it to lunge right over you, target its head in VATS, and watch the beast fly backwards.
Another meta example. Do you know how long it takes to make a console/PC video game? Usually companies take 2-4 years to make sure they get it right. Obsidian was only given... 13 months. Factor in that at least 2 months for pre-planning (confirmed by J.E. Sawyer) and at least a month of basic bug testing they made the entire game in ten months. Very impressive when you realize the scope of the game. On the other hand, a tearjerker for Obsidian as Sawyer let slip that they needed 5 more months to fully flesh out the game: specifically to add the post-game sequences and Legion territory.
The Riot Gear and the other two variants, the Advanced and Elite Riot Gear. They all have special effects which increase your Guns, Explosives, or Guns and Critical hit chances respectively. They also increase one special stat. Agility, Endurance, and Charisma, respectively (once more). The Elite Riot Gear also gives the second highest DT out of all the Medium armor, exceeded only by the Gannon Family Tesla Armor. It also has the highest item HP out of any Medium armor, period.
Having the whole town of Goodsprings drive out the Powder Gangers, especially if you've got a kickass song like 'Big Iron' on the radio.
Any way to take out Lanius is pretty epic, but sometimes the oldest ways work best. Like taking a light machine gun and simply unloading it into his head.
If you have the And Stay Back! perk, opening the fight by blasting the Large and in Charge giant that is Lanius flat on his ass is both awesome and funny.
Getting every casino in Vegas to forbid you from playing at their tables anymore because you're cleaning them out. You can rub it in their faces as well.
Going into Cottonwood Cove and murdering the hell out of the Legion during the quest An eye for an eye, recommended that you take Boone with you as doing the quest with him gives you history points towards opening his companion quest, but before doing so, if you have a lockpick of 100 (or 90 with a locksmiths reader on hand) head into the hills northeast of the cove where you will find the snipers nest, pick the lock on the gun case for the Gobi Campaign Scout Rifle, and give it to Boone and give him some .308 ammo and watch legion heads get popped like melons.
Alternatively, if you don't have a 100 Speech skill, a speech skill of 80 Speech (or at least a TON of Good Karma) will call out Lanius for a one-on-one battle to the death, with Lanius telling his Elite Mooks to stay out of it. This not only allows for a more thematic conclusion of "two men enter, one man leaves", but also effectively turns the battle into the ultimate Mirror Match if you've gotten the Armor of the 87th Tribe and the Blade of the West from Lonesome Road (see above).
For the ultimate in comfortable asskicking, get some sort of casual clothing, like Pre - War Relaxedwear or Sexy Sleepwear and play the game with just that, without any weapons or companions. If you make it all the way to Lanius and then beat him down in a mano e mano - congratulations, you've singlehandedly changed the fate of the Mojave without help from anything or anyone but your own pure skill.
Bonus points if you do it on Hardcore mode.
Killing a deathclaw is awesome by all means, but doing it unarmed is just plain badass.
There is a GRA challenge for killing adult Deathclaws using either the Silenced .22 Pistol, Switchblade, Dynamite, Boxing Tape, or Recharger Rifle. These are all the absolute weakest weapons of their respective categories.
Come Fly With Me. You just wanted a hotel room in Novac, a small community with a salvage based economy. You're asked to go clear some monsters out of a warehouse. Sounds like a basic 20 Bear Asses quest. What follows is perhaps the quirkiest and funniest quest in the game. You discover that none of the monsters (Nightkin and a couple of groups of Ghouls) want to be there but they can't leave till they find things that are trapped in territory held by other groups of monsters. In the conclusion of the story, you can help a cult of Zombie ghouls pursue their charismatic leader's crazy dream of finding nirvana by attempting to launch them into space in a 200 year old spaceship. You can even watch the launch set to Ride of the Valkyries.
The Legion-exclusive "Arizona Killer" mission. In one of the best missions in the game, Caesar tasks you with killing NCR President Kimball, who is making a public visit to Hoover Dam. Just before the climactic battle against the Legion. The absolute idiocy of this is lampshaded by Mr. House.
Mr. House: Aaron Kimball, the president of the New California Republic, is going to visit Hoover Dam to "boost morale". Apparently, he hasn't considered the effect on the troops' morale of seeing their beloved leader get his brains blown out by a Legion sniper.
And those are just the ways that Obsidian deliberately intended. If you want, you can roast him with a flamethrower, punch him with a Displacer Glove, destroy him with a missile launcher, atomise him with the Fat Man...
The existence and survival of Vault 21, located right under the Strip. Vault-Tec's shtick for this one was more or less to fill it up with compulsive gamblers. And while everyone was equal, differences and decisions were settled by games of chance. It's an arrangement that one would wager on failing, given the ruin the other Vaults in the Mojave suffered over time. And yet, not only did the Vault surpass even the Enclave's expectations, but it managed to work despite the odds thrown against it. The only time the Vault's lucky streak failed them was when House found and beat the inhabitants over blackjack... and even then the place was made into a hotel.
If you have completed Lonesome Road and have bombed the Legion, get the Armor of the 87th Tribe as well as the Marked Beast Tribal Helmet and a Blade of the West. Then go face Lanius. Best to be done with someone with a high Melee skill. Bonus points if you're playing as a girl.
Finally finding the treasure of the Sierra Madre. And then letting go...
At the end of the Dead Money DLC, you can lock Elijah inside the vault that he's been trying to get inside of for years, trapping him forever in an empty room. It's doubly impressive if you help all the other members of your crew let go of their baggage, get out of the Sierra Madre alive, get some gold for your effort, and stick Elijah with the tab. Not bad for a fellow American.
Honest Hearts features the quest Rite Of Passage, which lets you earn your place in the Sorrows tribe and get a unique weapon. How do you do this? By hunting down the biggest, baddest, on-fire-estYao Guai in the Fallout Universe. As if that wasn't enough, you do this while high on tribal tea.
The "Crush the White Legs" option in Honest Hearts. Particularly if you do it using Randall Clark's Survivalist's Rifle and Desert Ranger armor.
Joshua can and will annihilate the White Legs without any assistance from the player. In fact, the only challenge is convincing him to stop his Roaring Rampage of Revenge against the Legion's allies.
One of the few actual RPG-boss-like creatures comes in Old World Blues as the Giant Robo Scorpion. You can deal with it one of any ways: you can find the shutdown code nearby and remotely shut it down, use the Sonic Emitter to EMP it, or reconfigure the turrets to attack it for you.
Old World Blues lets you successfully win an argument with your own brain by pointing out that most of the glands it's complaining about are inside it. Yes, you just successfully outsmarted your own brain.
In Old World Blues, turning Dr. Klein's cohorts to your side by pulling on their last shreds of humanity, and then have them all turn on him (in hysterical ways) in the final confrontation. Dr. 8's speech is particularly moving, 0's is both awesome and hilarious.
Alternatively, you can pull a Bavarian Fire Drill by claiming it is not your brain that inhabits your body, but rather DR. MOBIUS!!! Not only do the successful speech checks prove that The Courier can do a pretty good imitation of Mobius' Large Ham antics, but it also causes Dr. Klein to have a giant Freak Out, and basically pee his nonexistant pants.
Learning Ulysses' question to the Think Tank that caused them to be knocked out of Mobius' loop, not experiment on him, and give him the information to reactivate what laid beneath the Divide. Who are you, that do not know your history? Goosebumps.
This moment from Lonesome Road, if you're a female Courier aligned with the Legion.
Ulysses: Last I heard, you needed a weapon between your legs to carry one for Caesar.
Get to the end of the Lonesome Road DLC. If you can successfully convince Ulysses to abandon his plan, then both you and he will team up in what appears to be a Bolivian Army Ending when Marked Men come flooding in to the silo to kill you both. That's right, the two Couriers, longtime adversaries, both incredibly strong, resourceful, and skilled, and with a number of incredible heroics under their belts, reach a common ground, and fight together. And win.
Hell, The Lonesome Road itself is pretty much this, in-game and out. The set pieces are used well enough to make a tense story, truly terrifying enemies in the form of the body horror Marked Men, the mutated Tunnelers and old standbyes Deathclaws. Add in several chilling events such as setting off an ICBM onto Hopeville half-way through the DLC, ED-E getting jacked by Ulysses for him to use in his master plan to blow up NCR and Legion, and whatever resolution is chosen, the result will be epic. So epic that people through the Mojave speak of the Battle of the Divide as one just as important as the Second Battle of Hoover Dam. Regardless of outcome, this moment is one of the big two Crowning Moments of Awesome in Courier 6's life.
Even fighting Ulysses to the death can count. Bonus points if you can tag-team with ED-E, play through the DLC under the recommended level, STOP the nukes from launching and by hacking Ulysses' eyebots. You, the player, with not even half of the amount of health that Ulysses has and with only a single robotic sidekick, are able to turn Ulysses' only allies against him, decimate him AND survive the oncoming onslaught of Marked Men that will flood the silo. Then you decide to heroically stop the nukes Ulysses intended to launch from launching by sacrificing ED-E and GTFO before the whole place goes up in flames. You then leg it back to the Mojave, knowing that you have save the lives of hundreds, if not thousands, from one person who wanted to kill them all.
ED-E gets one in Lonesome Road if you let him sacrifice himself to stop the launch. You can protest against it, but he's still completely willing to do it, and despite the damage it does to him, is able to play his battle music one last time as he zaps the console and fries up as the missiles explode harmlessly all around him.
Ulysses gets one for subverting Fallout's usual Arc Words by insisting that while War never changes, men themselves can change.
In the ending slide show of Lonesome Road, you've defeated Ulysses, either by talking him down or slaying him in combat, and now the Courier has to leave the Divide, making their way back through the devastated place. And the Marked Men, crazed cannibals held together with hate and radiation, and the Tunnelers, ferocious humanoids capable of swarming and taking down Deathclaws, stay out of your way.
There's a reason you win a challenge for merely setting foot into The Courier's Mile. But really, how bad could it be after the hell that was The Divide? Well you have to deal with:
1) Constant, heavy radiation in a place where the enemies will tear right through any anti-radiation equipment sans Power Armor (and even then...).
2) On your left, a dozen Marked Men, in an area that lets them regen health like mad (full health in half a minute), armed with some of the best weapons in the game.
3) On your right, a dozen special irradiated Deathclaws, grouped tightly together and with no sort of high-ground to save you. They'll kill fairly much anyone in two hits.
4) All in an area so small you can see the other side, ensuring you'll most likely aggro all the enemies at once if you're not careful.
There's some nifty loot, but nothing particularly rare other than some Mini-Nukes and a Nuka Cola Quartz, and there's only one unique item which isn't particularly showy. In all, it's a Bragging Rights Reward-sort of area, but surviving it means you have utterly mastered the game.