The opening. A scene with the four new vault hunters showing all their skills, backed by "Short Change Hero" by The Heavy.
Bonus points go to Zer0, who kills two Hyperion soldiers in what is arguably the most badass impalement ever. After tricking one soldier into punching his hologram, he runs the other through from behind with a katana, does a flying somersault off of his (still standing) body, and kicks off the first soldier, sending him flying right into the blade, chestfirst. Cutscene Power to the Max, sure, but undeniably epic.
The Launch trailer also shows us how awesome our new vault hunters are, against the army of Handsome Jack's mercs after the train crash from the opening, and that some familiar faces from the previous game have their backs. Special mention goes to Lilith tag-teaming with Maya to wipe the floor with a whole platoon of them before blowing them up and bumping fists, mouthing "boom". Totally Badass women. Unfortunately, this didn't appear ingame.
Lilith levitating, then teleporting Sanctuary.
Handsome Jack: That's the best you got, A flying city? What do you chumps have that could POSSIBLY make you think you've got a chance against me? Roland: A Siren. Lilith: 'Sup. * FWOOMPWSSSSHHH*
What makes this even more epic is how he says said catch phrase. Normally he says it in a slightly whiny tone befitting one of the series Butt Monkey's but after the above moment he practically roars it.
Taking on Terramorphus. Even if you don't win (which is very likely), just fighting him with three friends and not passing out at the sight of him makes you feel ridiculously awesome.
On your way back to Sanctuary after Bloodwing's death, you get attacked be an army of high level Hyperion robots. Just as you ready your favourite gun, you hear Mordecai tell you to get down... who then proceeds to unleash a truly massive attack, effortlessly wiping them all out with exploding slag Cobra shots.
Then, whenever you come back, he keeps on doing it.
Handsome Jack is a smug asshole the entire game, and pretty much any setback he has he just shrugs it off. Who's the first person to REALLY make him lose his shit? Moxxi, by sending you on a mission to flood the construction site of part of his city. Seeing him finally break out of his facade and genuinely angry is SUCH a cathartic moment.
Handsome Jack: AAAAAARGH!! MY CONSTRUCTION SITE!! MOXXI, YOU BITCH!!!
He reacts similarly to destroying his statues in the city. Especially when he acts like you're only mildly irritating him "for eight seconds" but then starts screaming in rage and promising to make a bunch of statues consisting of him kicking you in the junk.
"I'm gonna make, like, fifteen of those sumbitches, and put 'em up everywhere!"
Follow all of the Slab King's advice during Toil and Trouble to feel like a real badass, fighting your way to an elevator through a canyon of bandits, blowing up a bandit leader's ride in a explosion you Unflinching Walk away from, beating down multiple buzzards and stealing the Sawteeth clan's explosives before finally jumping off of their tower in the sky and landing in the middle of a group of likely respawned enemies.
Slab King: God-damn you make me proud, Slab!
Fighting alongside Roland after rescuing him from either the Bloodshot Ramparts or the Friendship Gulag can be pretty awesome for a former Roland player, especially when the Scorpio came out, and Roland was kind enough to spec into Aid Station and Stockpile for you.
Heck, fighting alongside any of the previous Vault Hunters can be like this.
The "Animal Liberation" mission. Few things are more satisfying than having a stalker, one of the most lethal and aggravating enemies in the game, fighting on your side.
Also in that ECHO-cast, kinda fridge awesome: Gaige, an 18-year-old girl, managed to build a robotic arm strong enough to smash through concrete, in one night, with one arm and only the spare parts lying around her backyard shed.Iron Man, eat your heart out.
Not to mention she deliberately cut her arm off so she could install the robotic one!
Attacking a Hyperion base to reach the bunker holding Angel head on can be considered this as you are pretty much storming one of Jack's most protected bases with the help of Brick's bandits. And from the same mission taking down the BNK3R
Killing Handsome Jack. After all the shit this lunatic puts you through, you get to enjoy him pitifully begging for his life after you defeat the Warrior. And it's not a cutscene death either. You get to pull the trigger on him yourself, with whatever gun you want, at any point during his speech. Thank you, Gearbox.
Allowing Lilith to kill him instead is just as satisfying, considering everything the original four Vault Hunters have been through.
The only thing that's anywhere near as awesome is playing as Maya and using your ownSiren powers '' to do so.
What's better than using a gun or a Hyperion firearm? How about ramming a salvo of kunai into his chest if you're playing as Zer0?
Alternatively, using the Scorpio assault rifle You receive from the quest where you inform Sanctuary's residents of Roland's demise to do the deed. The curious fire rate causes it to sound like an army salute drum snare, making your revenge all the sweeter and all the more symbolic.
Or the comedy of shutting him up with Gaige's melee, and hitting him on the head with a toolhammer.
Wanna make it a CMoH? Use the gun that Michael Mamaril gave you if you still have it.
Also for Salvador, spec'ing into the Brawn skill tree for the Fistful Of Hurt power, allowing for Sal to deliver the most devastating uppercut in the world, right into Handsome Jack's face!
Being Krieg in this situation is especially fun because all the things Jack says about you, (that you're a murderer, a bandit, a psycopath) are all true. The knowledge that you're all these things and more and STILL more righteous than him makes it so satisfying to land that buzz-axe into his soft face. Better yet, if he hadn't ordered those experiments on ya, you wouldn't be the badass standing there about to kill him.
Bonus points if you use your buzz axe, which is just like the one that his grandmother had used to discipline him as a child. Because nothing says revenge quite like forcing your enemy to relive childhood trauma while you kill them.
And of course, just the simple, basic melee attack. Nothing like an anti-climatic end for a over-the-top Smug Snake with A God Am I delusions.
Exploding round sniper rifle shot to the mask, anyone? This is for what you did to Bloodwing, you sunnuvabitch!
The point is: It's awesome and satisfying no matter how you do it, because the very people he said were dirt are making Pandora a better place.
Or the Morningstar, nothing says Irony like killing them guy with a gun his company sent you to make you feel bad.
Heck, there's also doing so with the first gun you get in the game. "Heh".
Whip out the Law revolver or any other gun with a bayonet, and happily stab him.
Or you could just take out Moxxi's Hyperion shotgun and blast him in the groin with it. Moxxi sends her regards, asshat! Oh, and it gets better-you killed him with a Hyperion weapon and a Groin Attack!
And if you want to give him the most agonizing death possible-get the SWORDSPLOSION!
Or, you could literally execute him with Zer0's Executi0n.
Landing a hit while having 400 Anarchy stacks. You'll miss a lot but when you do connect it is awesome.
Claptrap, of all people, screaming that he will Teabag Jack's corpse during Talon of the Gods. For the duration he actually drops much of his cowardice and is only stopped by the fact that he can't climb stairs.
Claptrap gets one also for coming up with a plan that actually succeeds in pissing off Handsome Jack, simply by destroying all of his statues in Opportunity. Please note, chronologically, this quest takes place before you kill Angel. This, along with Moxxi's sidequest, is one of the first times you actually manage to get under Jack's skin.
In "A Meat Bicycle Built for Two", Krieg saving Maya, and making one of the Rats faint simply by screaming at him.
"I'M GONNA PUT MY PAIN INTO YOUR SOUL!"
Good!Krieg managing to convince Insane!Krieg to help in the first place.
"TURN AROUND, PRETTY LADY!!" (Caves buzzaxe into a Rat's skull)
How good does it feel to play as Krieg in general? Psychos of various flavors are some of the more annoying enemies to deal with for many players, and most of the skills in Krieg's arsenal basically give you all of the tools that Psychos use against you. You can split heads with a buzz-axe, throw it, chase people with lit dynamite under your arm, strap dynamite to the axe before throwing it and even breathe fire. The class is built around delivering catharsis for having to put up with Badass Psychos and Suicide Psychos on all of your other playthroughs.
A small one for Sane!Krieg. He states to his Psycho side in no uncertain terms that if he ever hurts an innocent, he will wrest control away from Psycho!Krieg and commit suicide. Surprisingly, Psycho!Krieg listens.
The intro to Tiny Tina's Assault on Dragon's Keep has crowners for not only Brick, who tears his way through a heavily-fortified Hyperion base singlehandedly (and pumped up with will-weakening drugs), but for Tina. PARTICULARLY for Tina, considering how she manages to pull it off: by turning the drugs to her advantage, convincing Brick that he's an all-powerful Siren and giving him the strength to fight back.
The ending to Tiny Tina's Assault on Dragon Keep, where who else saves the day but Bloodwing!
Any fan of Westerns can appreciate seeing the Vault Hunters fan the hammer whenever they're firing a revolver really quickly. It's a simple detail, but it's nice, considering how the entire game is a Space Western at its core, behind all the science fiction and the war.