It's all the more chilling for its quiet, guilt-tinged delivery when Alfred in The Dark Knight reveals how his mercenary squad finally caught the Robin Hood-style bandit they were hunting after they couldn't find him and realized he didn't care about money:
As Hannibal so eloquently put it, "overkill is underrated."
The James Bond films are archetypal for their rather messy deaths, although most of them are not caused by Bond himself or are Karmic Deaths. Then Licence to Kill upped the ante with a Darker and Edgier Bond who had no qualms with dispatching enemies in the most violent way possible, culminating with sending the Big Bad to Hell via an exploding tanker truck.
The death of Sonny Corleone is the straightest example. Ambushed at a toll booth by a dozen Tommy Gun-wielding gangsters, he is 1) shot several dozen times inside his car, 2) then shot some more outside the car, 3) then shot on the ground after he died, then 4) had his face kicked in for good measure. The commentary for the film confirms that this is all a justified trope: they wanted to make sure Sonny stayed dead, given that his elderly father Vito had been repeatedly shot earlier in the film and survived, and that Sonny was known to be a tough bastard. (The generally accepted number of times Sonny had been shot is 147, incidentally.)
At the end of the movie, the montage massacre of the heads of the Five Families during the Baptism scene, along with Moe Greene and Tattaglia's mistress who had the misfortune of sharing his bed at the wrong time... and Carlo Rizzi, Michael's brother-in-law, for his role in Sonny's death. The body count for the end of Part II is relatively minor compared to Part I but aside from Hyman Roth's death, there was no real need for Michael to have the other two killed... including his own brother Fredo. It would take the mob boss massacre orchestrated by Joey Zaza in Part III to top the whole trilogy.
In Training Day, Alonzo Harris is a lesser version of this as a deliberate Shout-Out: first the Russians crash his car, then they shoot him in the car, and after Alonzo leaves the vehicle, battered, he is shot brutally on full-auto.
Predator might be a borderline case in that the protagonists are fighting an almost invisible opponent and just happen to have his approximate position known. But then, the six people are emptying two assault rifles, two sub-machine guns, a grenade launcher, and a minigun at a patch of jungle over the next 40 seconds, all the while reloading and continuing to fire. And they didn't even get a good hit.
This scene was utterly bizarre for a couple of reasons -1. only one of the characters even saw the creature or even had an idea of where it went. The rest just spend the entire time randomly shooting in the general direction just because Mac was doing so when they arrived. 2. The team was stuck in the jungle with only the resources they were carrying on their back. Considering #1, this seems like a tremendous waste of ammo. However, the very team itself could be considered to be this trope since they seem to be very well armed for what is supposed to be a commando extraction mission on foot. Not only do they have firearms, grenades, etc., they also have a significant amount of claymore mines and other explosives.
Just about everything. Giving a security robot Gatling guns? Sure, why not? How about making a new police robot as tall as a auditorium? Sure...
Given that RoboCop was rebuilt from the remains of a murdered police officer, it was kind of a foregone conclusion that Alex Murphy would die in the line of duty in a very horrific way. When ambushed and taken captive by Clarence Boddicker and his gang in a steel mill, 1) Boddicker shoots Murphy's right hand off with a shotgun at point blank range, 2) Murphy stumbles a bit, clutching the stump with his left hand, 3) Emil Antonowsky shoots Murphy's entire right arm off at the shoulder with another shotgun, 4) Emil and the other gang members - Joe Cox, Steve Minh and Leon Nash - empty their shotguns into Murphy's torso, 5) Murphy is still not dead (probably because he's got a bulletproof vest on), so Boddicker pulls a pistol and puts a bullet in his head at point-blank range.
Similarly, most of the hero deaths in Dillinger apply, though Pretty Boy Floyd (repeatedly machine gunned as he runs across a field) and Homer Van Meter (shot by a dozen heavily-armed farmers) deserve special mention.
He shoots the tour guide with a surface-to-air missile designed to take down passenger planes, blowing up the man and a huge chunk of forest around him.
The bomb he plants aboard Air Force One vaporizes the entire lake the plane's in — and it's not like it's a small pond.
In Rambo IV movie we are introduced to an un-exploded Tallboy bomb as the Mercenaries trek through the jungle toward the massacred Karen village. Later John Rambo sets up a Claymore next to the bomb while Burmese soldiers chase him. The Tallboy was developed by the British in WW2 (more specifically, by Barnes Wallis, he of the Dambusters' Bouncing Bomb) to destroy hardened bunkers and was at the time the single most concentrated repository of High-Explosive in a single weapon. The Claymore by itself is capable of invoking the Chunky Salsa Rule on everyone within a dozen yards, when it went off and caused the Tallboy to sympathetically detonate the results were... impressive.
At one point Rambo commandeers a jeep turret on which sits a Browning A2 anti-aircraft machine gun. The first thing he does is absolutely destroy another soldier in the jeep by liberally unloading into him about two dozen rounds, from a gun whose each bullet will blow a big hole into a human torso. Sure enough, the soldier's bottom half - and some gore on the gun's shield - are all that's left. Rambo then directs the gun's absurd firepower onto the infantry below, causing Ludicrous Gibs aplenty.
During said gunfight Rambo notices a patrol boat and targets it with the machine gun, utterly annihilating the crew and making it wholly inoffensive. The Karen rebels, not quite content with that, blow it sky-high with a rocket launcher.
Team America: World Police: Team America uses machine guns, rocket launchers, and missiles to kill terrorists, even if they are in a crowded city. They wind up destroying all the monuments and destroying the town, but hey, the bad guys are dead!
In the Robert Rodriguez film adaptation of Frank Miller's Sin City the character Hartigan, after knifing one of the primary villains of the piece in the gut and proceeding to "take his weapons away from him...bothof them," graphically and with his bare hands, then begins to brutally beat the bad guy's face in until "After a while all I'm doing is punching wet chips of bone into the floorboards. So I stop."
He did take Junior's other 'weapon' away once already, ineffectively, some years ago. This time, he was just making sure.
In Sukiyaki Western Django, Hiyomuri shoots a boy's father dead in front of him, then shoots him 4 more times once he's hit the ground and his wife is crouching over the body, who he then attempts to rape because he likes the look of her bathed in her husband's blood.
In Pet Sematary Two, after Edward Furlong's father kills the revived corpse of the sheriff, he leaves the house to go to search for his son. But just as he's about to open the door to his pickup, he stops, goes back in the house, empties the clip, reloads, empties the clip again, then leaves in his pickup! Zombies: Always Make Sure.
In Outlander, Kainan's people do orbital bombardment on a planet just to kill its natural inhabitants. Of course, given the amount of damage a single Moorwen did to the colony, this is perhaps a Justified Trope in retrospect.
One of Jason's first victims is the Jerkass Trey, who he impales somewhere around a half-dozen times with his machete. Afterward, noticing Trey's death spasms, Jason sets down his machete, grabs both ends of the bed, and breaks it (and Trey) in half.
Let's just say it; Jason Voorhees is the patron saint of this trope. Especially when played by Kane Hodder.
Halloween: The Curse of Michael Myers has Michael preparing to kill a bunch of sanitarium employees by overlooking a tray filled with medical tools. At first, it looks like he's going to grab a scalpel, but, having apparently gotten tips from Jason Voorhees, he decides to grab a huge machete (that was there for some reason) instead.
In Rob Zombie's Halloween II (2009), Michael stabs a nurse in the back. And then does it again. And again, and again, until after about an entire minute filled with stabbings, he rams the knife into her skull and leaves it stuck there.
Portrayed in a video game within Inside Man. A young boy makes his alter ego shoot many times at what must be an already dead man's head, and then he puts a grenade in the man's mouth. The lead bank robber, who is chatting with him at the time, is appalled.
In X-Men Origins: Wolverine, Logan brings down a helicopter and its mutant operator, who is then incapacitated and trapped. He could use his adamantium claws to stab his helpless victim, but decides instead to blow up the entire helicopter in a massive display of pyrotechnics.
In X-Men: Days of Future Past, this seems to be the Future Sentinelís general philosophy when taking out targets. As such they commit a string of ruthlessly brutal and outright cruel executions during the film, seemingly to ensure their targets are taken out for good. There is some cold justification for this considering how much punishment some mutants can take, though it doesn't make what they do any less horrific.
In the first movie, the Big Bad falls to his death. Then is run over by a bus. And then crushed by a steamroller. And then trampled by a marching band playing "Louie Louie". And Drebin's boss starts to cry, saying "My father went the same way!"
At the beginning of the same movie, O. J. Simpson's character is shot six times, then hits his head on a pipe, burns his hand on a stove, leans against a freshly painted door, gets his other hand caught in a window, falls face first into a wedding cake, and then steps in a bear trap before finally falling into the harbor. He survives.
The Narada, Nero's ship, is capable of wiping out whole fleets of Klingon Warbirds and drilling down to a planet's core. (The drill is left over from when it used to be a mining ship.) As soon as he gets his hands on Red Matter, a substance that can create artificial black holes, his raging overkill tendencies just get that much worse. He starts destroying planets with it. Just a bit of an Omnicidal Maniac.
Early in the movie, when the swarm attacks the Enterprise, thousands of impacts effortlessly overwhelm her shields and systematically strip her of deflectors, phasers, FTL propulsion and impulse drive, forcing her to crash on the planet.
Revenge of the Sith: After Aalya Secura is shot by the Clone troopers, they continue to shoot at her dead body afterwards.
A New Hope has the Death Star Superlaser The amount of energy required to destroy a planet is some eight - nine orders of magnitude greater than what killed the dinosaurs, and seven - eight more than required to just kill everyone. And the Death Star gives five - six orders of magnitude more than that. Not to mention, that they could have cracked the surface, or burned away the atmosphere, using a lot less resources (A Hyperdrive with the safety's turned off, for instance).
Justified by the kind of defenses planets in the Star Wars galaxy may have: Alderaan had a planetary shield that survived the Superlaser blast for a tenth of second. The designers still went overboard, but they had a reason for that.
Also justified by the fact that it was supposed to be a massively vulgar display of power which would get the attention of anyone even considering revolt. Much of the Expanded Universe states that they succeeded, but not quite the way Tarkin had hoped. His intention was that everyone would be too scared to oppose the Empire. (In his own words, "Fear will keep the local systems in line. Fear of this battle station.") Instead he inspired more anger than fear. Lord Vader, being quite the expert in both anger and fear, probably anticipated this but wasn't particularly bothered by it.
The Force Awakens gives us Starkiller Base, which goes one step further than the Death Star and blows up every damn planet in a given star system at once — from halfway across the galaxy! The power issues do get addressed here, though: the base is solar-powered, as in it absorbs a star to fuel its weapon... and if you take a look at the novelization, you find it rips its targets down to the subatomic level and scatters them across all the Universe and back.
Rogue One has Tarkin using the Death Star Superlaser to get rid of Krennic. It also qualifies as complete overkill as a measure to deal with the Rebels on Scarif, as there were less than a hundred actually on the planet's atmosphere at the time the weapon was fired while thousands of Imperial personnel were present and most of the Rebels had already been killed by those Imperial troops. The superlaser is literally fired directly through the antenna deck where the wounded Krennic is lying, and seeing as that was a less than ideal aiming point to wipe out the remaining Rebels (though the sheer size of the shockwave did the job anyway) there's no way this was a coincidence.
The Last Jedi: When Luke walks out on the battlefield alone to meet Kylo Ren, Kylo doesn't mess around: he orders the entire First Order army to blast Luke to smithereens.
In The Great Mouse Detective, Ratigan tries to dispose of Basil with an overkill-tastic Death Trap including a mousetrap, a crossbow, an axe, a gun (given that the characters are mice, it's more like a cannon), and a falling anvil, noting that he couldn't decide which method would be best... so he used them all. Of course, Basil is able to use the various parts of the trap against each other and escape.
Ernest goes to his con-artist friends for help and they sell him an enormous amount of fake anti-troll equipment. It turns out he only needed milk, but it's still impressively like overkill.
Ernest: (coming down the stairs with what looks like a whole lot of fishing gear, strapped with wires and making whirring sounds.) You see before you the state-of-the-art troll-fighter of tomorrow. This multi-directional unitized high-tech fighting machine is toll-free, mucus-free and comes equipped with fifteenmillion megabytes of double-density wayfer-thin alloy forming a virtual reality of modern troll extermination. (He heaves the large device he's carrying gun-like on his shoulder into his hands in a dramatic pose.) Need I say more? (He glances down at Lady Hackmoore who is decidedly unimpressed).
Really, for not knowing about the whole milk thing, Ernest had overkill coming out the whazzoo. He set up traps in dumpsters for that troll!
Tom: Fourteen cans of troll-away spray nineteen ninety-five apiece. Two Bolivian Army slingshots, nine ninety-five each... troll ninja ninchucks... slime-proof troll gloves... chopped troll bait... fifteen no-troll strips... one trolling motor... for a grand total of... Ernest: Does that include the giant album of every troll love song ever written?
Also, when they were building the treehouse. They had pizza tossers, dog-food gatling guns and a helicopter bomber.
The fate of Cyrus the Virus in Con Air: beaten to within an inch of his life, smashed through a bridge on the extended ladder of a moving firetruck, gets electrocuted after he falls off the ladder, dumped on a conveyor belt, and his head smashed by a piledriver (the machine, not the wrestling move). He doesn't get better.
District 9 features several varieties of alien weapons. Most result in Ludicrous Gibs, all work on this principle. And it is oh so satisfying.
In Inglourious Basterds, Hitler and Goebbels were riddled with bullets, blown up with dynamite, and the cinema they were in was burned to the ground. Other high-ranking Nazi officers suffered similar fates as well, although not as bad.
Kenneth Branagh's version of Hamlet. Hamlet not only stabs Claudius with his fencing sword, he also drops a chandelier on him and, while Claudius is pinned down by said chandelier, force-feeds him poison.
In the spoof film Wrongfully Accused, Leslie Nielsen's character is convicted of a murder he didn't commit, and is sentenced to be executed "buffet style": Hanged, lethally-injected, electrocuted, and placed before a firing squad.
King Dinosaur has a group of astronauts exploring a rogue planet that's drifted into the solar system, and discovering a giant iguana among its native animals. After being forced to flee from it, one of the astronauts calmy announces "I've brought the atom bomb", and they proceed to nuke the giant lizard. As stock footage of a mushroom cloud fills the screen, the heroes proudly announce, without a trace of irony, that "we've brought civilization to Nova."
Final Destination: After the cast cheats Death, they begin to die off one by one. Most of these deaths were simple death by bus, decapitation, etc., except for one. For some reason, Death seems to really hate Ms. Lewton, the teacher. First her computer explodes, which lodges a sharp piece of glass into her throat, then the spark from the explosion causes fire which spreads inside her house. As she staggers, she falls down and manages to get stabbed by her own kitchen knife, then the gas cooker door blows open, spewing out gas. Then to top it all off, thanks to the gas, the entire house explodes. Sure you don't want to divert a meteorite to crash into the wreckage just to be absolutely sure, Death?
How do you kill the remaining two villains? Bomb the two-engined cargo plane they're in with gold bars until it explodesin a huge fireball.
In the pilot of the series, they're shooting bazookas at people during one shootout.
In Ghostbusters II, we learn that Vigo the Carpathian was "poisoned, stabbed, shot, hung, stretched, disemboweled, & drawn and quartered" (replied Peter Venkman upon hearing this, "Ouch."). After all that, he still managed to say a few words before his head died...basically declaring that even this wouldn't be enough eventually. He came darn close.
The Self-Destruct Mechanism for Resident Evil: Degeneration probably counts. In sequence, it consists of: drenching the contaminated areas, up to and including the whole facility, in flammable decontamination fluid, igniting said fluid, dropping the contaminated sections down a 3000ft deep shaft, blowing them up again, and then, if the whole place is contaminated, sealing everything under a steel cover thick and tough enough to withstand a nuclear blast. Admittedly, they are working with some of the most lethal infectious pathogens on the planet, but it's still a little overboard. Considering what has happened in Resident Evil before when these lethal infectious pathogens get out, you can never be too careful.
Undercover Brother's Mr. Feather is dropped out of a helicopter over the ocean. Just before falling hundreds of feet (the impact alone of which would've killed him instantly) a great white shark leaps out of the water, and eats him.
In 300 and Hero, Leonidas and Nameless are each killed with a Rain of Arrows plentiful enough to fell a whole regiment. Though in Leonidas' case, he was with a regiment. Most of them had died by that point, but still!
The captain of the salvage team in Event Horizon, after having found out that the titular ship was possessed by infernal forces, was inclined to fire missiles at it until it's vaporised.
In Shooter, a Gun Nut recounts the story of a sniper who was infamous for his brutality on the battlefield. The opposing side despised him so much that when they corner the sniper in the building, instead of trying to flush him out, they just bombarded it with enough artillery to level an entire city block. This is standard tactics for dealing with snipers, just not usually while they're in urban areas.
It's POV Prequel, Flags of Our Fathers shows the business end in detail for around half a minute. Everything from medium caliber Anti-Air guns to the largest-caliber 16-inch battleship shells are practically thrown at the island in full force, both before and during the invasion of Iwo Jima.
The series has VERY pragmatic "terrorists" (there's always a twist on what they really are in each movie, usually thieves). Even when McClane was a nobody, and when the bad guys thought it was just a random guy, they took no chances and attempted to kill him several times, prompting John's Properly Paranoid moments on the walkie talkie.
Then there's a scene in the second movie where the bad guys shoot at an airplane cockpit with machine guns, filling it with bullet holes, and then throw all their grenades just for good measure. When they see him parachuting out of the explosion, they just call him (again pragmatically) "Lucky Bastard".
One character goes after a wasp with a double-barreled shotgun after it kills her boss, the mayor. It takes three tries, but she does eventually kill it... after destroying a chandelier, corkboard, and an office chair.
Later they graduate to flamethrowers, and end up blowing up the swarm with about six propane tanks. Soaked in lighter fluid.
In Bruges: Ray kills the priest with many, many gunshots, even though he was at close range. A few of those unnecessary shots had gone off-target and killed a little kid.
The death of a revived Doras in the Decadefinale movie isn't quite as over-the-top, but close. He gets taken out by no less than twelve Kamen Riders, ten of whom were in their Super Modes, hitting him with their respective finishing attacks.
A feat nearly equaled in the Chou Den-O Trilogy, where Diend's Complete Form summons copies of eight movie-exclusive Riders, with all nine of them performing their finishers en masse. The opponent in question wasn't even nearly as strong as Doras, making this an even bigger case of overkill.
ACME Chairman: You see, if the Train of Death doesn't kill him, then those crates of TNT will. Not to mention the 2-tonne anvil hanging over his head, and- Oh, look. There's the Pendulum of Doom! What's the Pendulum of Doom doing there?! I did not order the Pendulum of Doom! It's overkill! Get rid of it!
And the famous lobby scene. You really start to wonder whether the advantages of carrying a loaded and ready gun outweigh the rather more severe disadvantages of having far less ammunition to work with, as well as the sheer amount of weight and bulk that carrying over a dozen guns would impose on the wearer.
Burt Gummer of the Tremors franchise lives and breathes this trope.
In the first Tremors, he and his wife unload multiple machine guns, assault rifles, an elephant gun, and even a flare gun into a Graboid. Then, he makes home made bombs that're powerful enough to make their guts airborne when exploded underground.
In Tremors 2: Aftershocks, he kills his first Graboid with 4 pounds of C-4 (which even he admits was excessive). And then kills another with a cluster bomb. Then, he shoots one of the Shriekers with a .50 caliber anti-tank gun with a solid bronze bullet (though that one was justified in that it was the last bullet he had). Then they detonate 4.5 tons of high-explosives and reduce an entire oil refinery to a large crater to kill the remaining Shriekers.
In Tremors 3: Back to Perfection, he blows up his entire house to kill a single Ass Blaster. And then he finds out it was completely unneccessary.
In Tremors 4: The Legend Begins, his ancestor buys a 2-inch bore Punt Gun and uses that to kill a Graboid. (For the uninitiated, a Punt Gun is a big...big shotgun. Sort of More Dakka, but only needing one pull of a trigger. The name come from the fact they were so large, to be used for their intended task they had to be mounted to flat-bottom boats known as 'punts'. Oh, and their purpose? Harvesting entire flocks of ducks....with one shot.)
The Punisher (2004): Castle just doesn't kill Howard Saint, but also just about everything Saint cares about. He sabotages Saint's money-laundering operations and then gives the money away. He then causes a rift with Saint's Cuban partners. After following both Saint's wife Livia and his best friend Quentin Glass, he creates the illusion that the two of them are having an affair behind Howard's back (despite the fact that Quentin is gay). When Howard finds out thanks to Mickey (who is Castle's mole), he stabs Quentin to death and then throws Livia over a bridge; she survives the fall but can't get off the train tracks in time and gets run over by a train. After he kills all of Saint's men in the club, he rigs a trip-wire grenade and forces his son John to hold up the grenade, where he eventually tires out and is blown up. An injured Howard tries to run, but Castle ties him to a car and sends it towards a parking lot, where he has rigged several hidden bombs that blow up as the car dragging Howard passes by, which light Howard on fire before that car blows up and we get an overview shot of the flames in the shape of the Punisher's iconic skull. Saint's an asshole that had it coming to him, but damn, what an example of overkill. To top it all off, Castle calmly explains it all in detail to Saint before finishing him off.
Overkill for an Overkill... the Saints, Glass included, were being Punished for killing his ENTIRE FAMILY, I'm talking at least 3 whole generations, as payback for the accidental death of their son during criminal activity.
Ordell Robbie: AK-47: the very best there is. When you absolutely, positively got to kill every motherfucker in the room, accept no substitutes.
In The Raid, Jaka kills a mook with three point-blank headshots. When the residents attack the SWAT van, they open up on full-auto and just keep firing.
The Jericho missile, in Iron Man. To elaborate, Tony Stark built a missile that can flatten an entire mountain, and it isn't nuclear. Nope. It's just one large missile that splits into a thousand smaller warheads. The shockwave from the demo blasted off the generals' caps from the horizon.
Tony Stark: They say the best weapon is one you never have to fire. I respectfully disagree. I prefer the weapon you only have to fire once.
The poor Mook from The Expendables 2. After rounding a corner, he happens to meet up with the entire crew, who have just made mincemeat out of a small army of bad guys. He gets ventilated by every one of them at once.
Barney: Rest in pieces.
The Usual Suspects: "He lets the last Hungarian go. He waits until his wife and kids are in the ground and then he goes after the rest of the mob. He kills their kids, he kills their wives, he kills their parents and their parents' friends. He burns down the houses they live in and the stores they work in, he kills people that owe them money. And like that he was gone."
The opening death scene of the two girls in Suspiria.
In Dredd: Ma-Ma uses a set of three supercharged Gatling guns to absolutely decimate an entire level of the block. This actually ends up as a plot point, as Dredd realizes no one would go to such lengths to kill a Judge unless they had something big to protect.
Pacific Rim: How do you Double Tap a kaiju? You fire your plasma cannon into its chest until most of its torso is a burning skeleton. Granted, Raleigh had a very good reason for this his brother Yancy got killed at the beginning of the movie when a kaiju they thought dead turned out to have a quite a bit more fight left.
Hard Ticket to Hawaii has an assassin who rides around on a skateboard carrying a gun in one hand and a blowup-doll in the other. The heroes hit him with a truck. While he is flying through the air, they blow him up with a rocket launcher. Then they blow up the doll with another rocket.
Dieter Von Cunth from MacGruber after he survives getting his hideout blown up and attacks MacGruber at his wedding, MacGruber headbutts him off a cliff, shoots him half a dozen times as he falls, when he lands he hits his head on a rock splitting it open and spilling his brains out, MacGruber then blows up his corpse with a grenade launcher then pisses on it.
Virgil's death by interrogation in True Romance: Virgil beats up Alabama, trying to find out where Clarence and the drugs he stole from Drexl Spivey are. Throwing her into the shower, she blinds him with shampoo, hits him over the head with the toilet cover, then sprays him with hairspray, stabs him once, and blasts him to hell with a shotgun, and once she's used up all the shells, strikes him with the shotgun barrel for good measure.
In the first ever animated Disney film, Snow White and the Seven Dwarfs, the evil queen is struck by lightning (well, really it strikes the cliff she's standing on). She falls over the cliff, and the boulder rolls off after her. What's left of her is presumably scavenged by vultures afterwards.
Conan the Destroyer: after Conan rips off Dagoth's horn, he impales the slain monster's head with his sword, prompting the theme music to swell triumphantly. Malak, the Lovable Coward and shameless glory hound, decides to get in on the action and stabs the dead monster with his tiny dagger, causing the triumphant theme music to swell all over again.
Brawl's defeats and eventual death. Arm chopped off by Ratchet. Shot up over and over again by Jazz and humans. A grenade detonated against his chest, knocking him out. Once he gets up, is still getting shot up by humans, and then gets his spark blown out by Bumblebee's plasma cannon. Lennox puts it best:
Sideswipe of the Autobots takes on (possible dimension-hopper) Sideways of the Decepticons. Does he shoot him? Does he stab him? Does he cut him in half like a lot of deaths in these movies? How about all three? First he flips into the air and shoots, perforated his car mode bilaterally. Then, he launches his sword down into the other's hood while in midair, hits the ground with both wheels, spins, grabs the sword, and bisects this mofo lengthwise.
Damn I'm good.
Three Decepticons take on Optimus Prime. They are Megatron, Starscream, and some other guy we don't care about, but he's huge. Optimus still almost wins. He mutilates Starscream, rips off the Big Guy's face, and brutally beats Megatron. But he's also kicked in the face hard enough to shatter his face-plate. Then shot in the chest with enough force to launch him across the forest. And once the battle is over, Megatron sneaks up and stabs him through the chest while lifting him in the air. Oh, and the blade is attached to a gun, which Megatron then shoots off. The hole it leaves is big enough to walk through.
Epps calls for an airstrike. Cue the B-2 Bombers laying down a carpet of explosives thick enough to block out the sun, followed by a display of Impressive Pyrotechnics that actually set a record for biggest practical explosion in a movie.
He doesn't kill Megatron, but at the end Optimus hands him his metal ass pretty good. A straight-up beat down with guns and swords first. Then he twists Megatron's gun/sword arm around and uses it to shoot off half his face. Finally, Optimus uses the jet engines on his back to blast Megatron through a wall. The Decepticon leader is missing one arm, half his face, and various other parts of his body. His response? "Starrrrschream!"
Megatron's plans. As The Dragon to the Fallen, he started a war on Cybertron to eventually take over the galaxy for his master. The Allspark was key to victory in that war. But in the event it was destroyed, he already had a deal with the Fallen to use the last Star Harvester to get more energon. Except he was playing his master. Really he just wanted Optimus to get the Matrix so the Autobots could bring back Sentinel Prime, which would lead to their own destruction when Sentinel switched sides.
Sentinel has a rust gun that causes any metal to dissolve. When he switches sides, he shoots Ironhide with it not once, not twice, but three fucking times! Immediately before that, he gave a short Breaking Speech to the Autobots and Humans. Between the second and third shots, he gets in a Pre-Mortem One-Liner.
I hereby discharge you from duty.
This film does a pretty good job of Deconstructing the idea of an alien invasion. As such, the Invasion of Chicago is filled with overkill. The Decepticons have Flying Aircraft Carriers, several types of airships, hundreds if not thousands of troops, and a giant metal worm that tears through rock like tissue paper. They unleash it all on Chicago. When they're done, the city resembles the radioactive Chernobyl site from the film's opening. The Decepticons also seem to enjoy shooting at random buildings and small groups of civilians with their fighter-ships.
On that note, the Decepticons' weapons are this for humans. While they might do a lot less damage to Cybertronians, the Con's weapons unleash pulses of energy (instead of simple plasma blasts, bullets, or lasers) which rip a human's flesh from their bones, and then completely shatter most of said bones into fine powder. Without a Gory Discretion Shot by the way.
Shockwave's death. First he gets his eye sniped at by humans. Then another group of humans appears in the building right next to him and blasts him with enough machine gun fire to tear off half his armor. Then Optimus Prime comes in and uses some brass-knuckle-like weapon to gouge out his guts. Then the Prime reaches around to behind his neck, grabs the bundle of wires that is like a cross between optic nerve and spinal cord, and rips it out. To add insult to injury, he uses Shockwave's own cannon to shoot down the Space Bridge Pillar.
Ratchet's fate. Poor Ratchet. He's hiding in the smokestack of an old steamer ship when its blown up by humans. Then when he tries to get away, he's shot up with missiles and machine guns, forcing him to transform. His leg is blown off. He pleads with the humans to have mercy, because he is, after all, just a medic. Then Lockdown gets involved. Between him and the humans, Ratchet is reduced to little more than a torso with some limb stumps hanging off. Then Lockdown pulls Ratchet's spark out from his chest and crushes it. Oh, and after he's dead? The humans who helped kill him sell his parts to a company that melts them down. Optimus was pissed when he found out.
Hound seems quite fond of invoking this trope. He threatens to splatter Joshua Joice, hits an alien bug thing with a plasma blast that makes it explode (just because it sneezed on him), and kills a ton of KSI Prototypes with more force than reasonably necessary. He also shoots his guns into the air to celebrate Optimus' return, and shouts with joy at the sight of giant (by Autobot standards even) robot dinosaurs obliterating the Prototypes.