Harley names the submarine she and the Joker stole "Gunter" and says goodbye to it.
And then Green Lantern turns up, commenting that Gunter is a terrible name for a submarine.
The interactions between Harley Quinn and Green Arrow in the prequel comic. Particularly, her calling him out on how stupid a name the "Arrow Cave" is, and noting that the Bat Cave is called what it is because bats live in caves. She recommends that he change the name to "The Quiver", which even Green Arrow agrees is a better name.
Also, the talk about the boxing glove arrow.
Harley Quinn: Why do you need a boxing glove arrow?
Green Arrow: Because sometimes I want to punch someone who's a really long way away.
Wonder Woman: You're right to fear. You fear Superman because you believe he could succeed. What becomes of the God of War in a world without conflict? Maybe you could become the god of something else? Something less violent. Say it with me. 'I am the dreaded Ares, God of Ponies!'
The payoff? After Supes and Diana kick his ass, he actually seems to be considering it.
Aquaman's reaction to Billy's denial of the Kraken as a myth.
Dick: Damian, you're 13 years old. How are you the darkest thing in this cave?
Calendar Man in Issue 15. Nobody recognizes him.
Calendar Man: Hey, hey, Wonder Woman! Do you remember me? Last week, I was trying to steal Faberge eggs and you broke my collarbone and punctured my lung with one of my ribs. Best date ever! *downcast* You don't remember.
Also in issue 15, after Batman causes a computer virus to mess with Cyborg to prevent doors opening to let Flash from taking various immates of Arkham Asylum to another unknown place, Cyborg realizes Batman put the virus in him the first time they met. Killer Croc's response?
Cultist: We don't answer to you. We serve only Him.
Green Arrow: I'd take your religious fervor far more seriously if you weren't wearing a dressing gown in public. Seriously, did someone sew the Superman symbols on or can you get them like that online?
Cultist: I bought this online! *brandishes shotgun*
A heartwarming kind of funny in Issue #28: Alfred has a list of what Bruce might want to take with him in case he ever has to abandon Wayne Manor in a hurry (which he has to, since Superman revealed his secret identity to the world as retribution for Batman sending the Martian Manhunter to spy on him disguised as Hawkgirl). When Bruce tells Alfred that he should leave him to save himself, Alfred informs him that he can't leave him, he's the first item on the list. We even see the list, and there it is: "1. Alfred".
Superman exposing Batman's secret identity. Whilst the plot-point is a pretty serious one, how it happens is downright hilarious. Batman causes a blackout in the broadcasting communications of the Watchtower just as Superman is about to expose him worldwide as Bruce Wayne. So with no apparent way to expose him, how do they get around that? They post "Batman is Bruce Wayne" on Twitter.
The entire sequence in Issue #31 with Green Arrow and Black Canary getting into one of Batman's secret hideouts via a restroom elevator, involving a retinal scan.
Green Arrow: I don't know what scares me more, the fact that he has our eyes on file or that the toilet is talking.
Even though he knows he's pretty much outmatched, Ollie manages to get some final snarky moments in Issue #33.
Superman: The U.S. government just ordered my death. Do you know anything about that, Ollie?
Green Arrow's chapter has quite a few amusing moments.
When discussing Regime Superman's status as a Fallen Hero, Insurgency Batman mentions that his universe's Green Arrow was killed trying to get through to Superman. With the "normal" universe Green Arrow standing not five feet away.
Green Arrow: *suddenly uncomfortable* …Alright, moving on.
After Green Lantern tackles Solomon Grundy out of Wayne Manor:
Green Arrow: You kids have fun! Stay out of the street!
After Green Lantern returns from the above, he casually mentions that he got rid of him by throwing him into orbit. Wonder Woman is shocked. Batman's totally unconcerned quip:
Batman (totally nonchalant): "Grundy's a zombie, he'll be fine."
When Insurgency Batman needs the normal universe's heroes' DNA for a scanner, all the hands are Color-Coded for Your Convenience. Batman is blue, Wonder Woman is red, Aquaman is orange, Green Lantern is green, but Green Arrow is…
Green Arrow (incredulous): Yellow?
Immediately before that as Batman digs out the rock containing his last resort weapon.
Green Arrow: A rock… You're gonna throw a rock… at Superman…
After all that Regime!Wonder Woman hasdone, it's funny to hear Deathstroke refer to her as "Superman's rebound girl."
Sinestro beats the normal universe Superman with a construct mace, and once done, asks Yellow Lantern "Not so super, was he?" …Only for Superman to tap him on the shoulder, counter Sinestro's punch, and then slowly, slowly take off Sinestro's ring.
The Joker's story mode. Anything he does (except him beating Batman) is funny.
Taking a drive through Gotham in the car of a police officer he just killed and having a conversation with him.
Joker: Thanks for the ride. You're a funny guy. Are you sure the old gang lives around here? True… Here, they could be dead… Law abiding!? Bite your tongue!
When the Joker meets Insurgent Harley for the first time:
Joker: Harley, it's me. I'm the Joker! It says here on my underwear! *points at his pants*
Harley: *shoots at him* Not funny, creep!
After the Joker's speech, the New Regime busts into the Joker Clan's meeting and open fires on to everyone, including Joker. He's just taken the durability pill, so the gunfire does nothing. His response?
Joker: I should be dead! Thanks, Happy Pill!
Then the Mainverse heroes come in, and Joker's completely nonchalant.
Joker: Hi, gang! What'll we do now? Anyone up for pancakes?
Wonder Woman: Joker!
*Wonder Woman grabs the Joker's arm tightly and twists it behind his back*
Also, the two times Ollie says "Shit". They're quick, but you can't help but snicker at them.
When the Joker and Batman are pulled into the Regime universe, the former turns to the latter and almost immediately declares "This is somehow your fault!"
Well, he is right, if you think about it.
After the Flash defeats Sinestro, he muses to himself that he can't just leave him lying there. So what does he do? Use his Super Speed to build a small pyramid over the unconscious Sinesto. Of course, Sinestro gets out by the time of good Superman's arrival in the Injustice universe.
During Lex Luthor's chapter intro, where he ends up crashing from the sky onto an APC, the Joker arrives just as he's getting up and summarizes it as only he can.
Joker: Humpy Dumpty fell through a truck… Humpty Dumpty's suit is all f–.
Nightwing interrupting Lex's gloating in the opening chapter:
Lex Luthor: Most of the League dies, and Superman's beloved city is vaporized. I console the masses by offering to rebuild it, in my own image of cou...
In an interview with Comic Vine, Ed Boon expressed that Hawkman would not be in the game, though he would not disclose the reason why beyond personal issues. Cue panel of Hawkman declaring "Risk my life to save Midway? NEVER!"
If you're a Mortal Kombat fan, you'll find this one funny. When Batman uses his grappling hook to grab an opponent in the air, he says "Get down here!"
Harley Quinn's Supermove. After stunning her opponent with her mallet, causing them to stumble back, Harley charges forward with a battle cry, fist raised... only to slide between the foe's legs, laying an explosive cream pie between them in the process. She even does a child-like "fingers in ears" crouch as the thing goes boom and the opponent flips head-over-heels over her.
Some of the stage transitions are pretty amusing.
The transit from Luthor's Lab to the Command Center of Insurgency. In a rather slapstick fashion, the combatant lands on their back, gets smushed under a large press as they try to get up, gets smushed again as they try that again, and then flung into a swinging mechanism that whacks them like a baseball across the room (and through several armor sets and a vent) into the starting area.
The Humiliation Conga transition from the Mess Hall to the Cell Block at Arkham/Joker's Asylum. The transitioning combatant is knocked into the rec room and hits Killer Croc, who angrily throws them by head into The Penguin, who slams and hits his umbrella on the combatant, who is then knocked over to Two-Face who slams a TV down on their head, forcing them to stumble into the Riddler's swinging cane, right before Croc comes back to punch them hard enough to knock them into a wall into another room.
Also at the Asylum stage, the other transition has the player bursting into the Scarecrow's cell. Rather than thank the player and be on his way, Dr. Crane seems upset that you've ruined his quiet time. So he injects the player with fear toxin, gives a hilariously over the top giggle, and sends you to his Arkham Asylum dreamworld, at which point he grows to giant size, smashes the player with his fist, picks the player up, and throws him/her through the floor and plummeting into the void... or rather, the kitchen. Somehow.
The Watchtower's transition from the Bridge to the Reactor. You knock the opponent hard enough to send them flying through multiple ships before falling off the ledge multiple stories before landing on the base of a giant cooling fan on their backs, right before the last ship they hit falls off the ledge on top of them (with an appropriate Oh Crap reaction to boot), smashing them through the fan and into a room with a miniature sun, which spits them out onto the floor.
The Gotham City Alley to Rooftop transition. Launched by an exploding vehicle and striking a few things on the way up? Okay, fair enough. But bouncing from building to building in straight lines? On a descending fall, that might be painful, but going up, it looks amusingly silly.
The Hall of Justice's transition from the Great Hall to the Plaza. Your target is smacked into a Boom Tube that leads to Darkseid's throne room, of all places. The obviously displeased ruler of Apokolips immediately gives your opponent a walloping before tossing him or her back out the Boom Tube (now leading to the Hall's exterior) with a final Omega Beam blast as if to say "And stay out!"
Themyscira's Temple to Port. Another Trauma Conga Line, the opponent smashes into a statue, falls from the statue onto some stone steps, bounces down said steps, crashes into a lit brazier, flips over the brazier over a cliff, smashes into several trees on the way down, crashes into the cobblestone docks, and then the head of the statue s/he smashed into (which was knocked off in the initial crash and rolled after the opponent) promptly lands on top of him/her before bouncing off into the sea.
The Batcave transition from the Lagoon to the Crime Lab. You smash the target into an elevator… then promptly leap in and deliver a flawlessNo-Holds-Barred Beatdown throughout the entire ascent, denting the poor thing everywhere in the process. It's especially funny if someone like HarleyQuinn is delivering the beatdown to someone like Doomsday.
Some of the stage interactions are fairly amusing.
The Flash doing an "offensive" interaction with a car = Super Speed head-slamming.
In the Metropolis "Museum" subsection, one of the interactive options is a rocket-propelled grenade launcher that Gadget characters can pick up and shoot at their opponents. What do Power characters do? They scrunch it into a little ball and lob it like a hand grenade.
In the Stryker's Island "Cell Block", Gadget characters can interact with the guard on the left of the arena by grabbing the guard's gun, shooting his/her opponent, and handing it back to the guard like nothing ever happened (Batman is an exception).
Slamming an enemy's head into a robot's crotch will never get old.
Batman's S.T.A.R. Labs training mission, if only for how depreciate the first objective is worded:
Show Nightwing how rusty you are.
Sometimes during Grundy's Pain Chain (which can last for a while), specifically the attack booster, when Grundy performs the last maneuver (a reverse tombstone), he says "Grundy don't stop." The delivery makes it work.
Quite a few of the Clash quotes are amusing.
The Joker vs. Batman
Joker: Smile! Batman (deadpan): I am smiling.
Joker: Funny meeting you here. Batman: Shut it, clown!
Aquaman vs. Superman
Aquaman: What makes you think you'll win? Superman: I'm Superman.
Solomon Grundy vs. Green Arrow
Grundy: Arrow man no hurt Grundy! Green Arrow: Arrow man yes hurt Grundy.
One of his "hurt" sounds (specifically, the one used whenever he gets shocked) sounds more like the waggling of one's cheeks than anything painful.
His back-dash is a silly little twirl.
The Joker's fight intro.
Joker: (as a dead cop, fake Irish accent) Watch out, Joker! This one looks kinda tough! (tosses the cop away) Really? I think you underestimate me!
In Lobo's DLC reveal trailer, his super consists of him whipping his opponent with his hook and chain before hitting them with his bike into the air, shooting them, then burns them up with fire coming from the bike all while giving the (censored) finger.
Scorpion's intro - he's just about to finish Sub-Zero, only to be teleported to the Injustice universe. Needless to say, he's not happy about it.