Ben 10: The Omnitrix has a self-destruct device that destroys the universe. Could be because its creator is a misanthrope, or whatever you call someone who dislikes everyone, regardless of species (An ''Omni''cidal Maniac, perhaps?) Or just wanted to be absolutely sure it stayed out of the wrong hands. However, this depends on how long the timer is set: when Ben sets the Omnitrix to self-destruct in 30 seconds in the Grand Finale of Alien Force, only the Omnitrix itself is destroyed; Ben explains that it would only destroy the universe if it charged for days like that first time.
Megas XLR: The entire idea of the series was based around overkill. So much so that Jersey City was destroyed in just about every episode. One of the most notorious examples involved Coop sending the planet into a nuclear winter just to defeat the Monster of the Week.
Several times throughout the series, while fighting another Humongous Mecha, Coop would look down at the dashboard of the Megas, which seemed to change from week-to-week, and find hilariously appropriate buttons to push, such as: three buttons in a row, labeled "Missiles" "Lotsa Missiles" and "ALL DA MISSILES"... guess which one he chose? All three.
Going for his "save the world" button, he found it was out of order, but "Destroy the world", "Smite the world" and "Destroy the world WORSE" were perfectly fine.
The absurdity of the overkills, however, sometimes went beyond physics, as, on two separate occasions, the Megas opened up its chest, and out came the main gun of an iconic anime spaceship - the first, in the pilot episode, was the main cannon and front hull of the Battlestar Yamato from the series of the same name; and the second, in an episode close to the series finale, was the main guns of the SDF-1 Macross from Super Dimension Fortress Macross.
By and away the greatest moment of overkill in the series is Coop's imagined destruction of the DMV. He stomps the building to pieces, then punches the pieces to bits, then blasts the bits to smithereens, pauses, and then blasts the smithereens into whatever is smaller than smithereens. All while laughing maniacally.
In the episode "Breakout", the bad guy is invisible. How do you hit an invisible foe? Simple. Fire off every single weapon you've got.
In "Universal Remote", Coop manages to give the Monster of the Week a shield that will reflect anything he shoots at it. His solution? Hit it with something bigger. Cue Jersey City getting utterly nuked.
Despicable Me. At urging, Gru enters the girls he adopted at a shooting gallery, and discovers the main target actually can't be knocked down with the guns provided. Regardless of how much he actually cared about the girls at this point, Gru clearly isn't happy that he got cheated, so his solution? He has a go, and uses a ray gun to level the whole stand. The man who cheated them decides to give Gru the prize after that.
Brock Samson of The Venture Bros. goes through Mooks like there's no tomorrow, often killing them in inventive and ultimately unnecessary ways. Like Bond, he has a license to kill so he can get away with it usually.
In Mulan, the villain Shan Yu charges his entire army against what is about 30 or 40 soldiers. Naturally, the Conservation of Ninjutsu wasn't on his side.
In an episode of Stroker and Hoop, Santa Claus (yes, Santa and no, he was not Bad Santa) shoots the guys who tried to kill him and Stroker and Hoop have to tell him to stop shooting, as they are dead.
The second half of the series premiere for Superman: The Animated Series subverts this. The giant mecha slams Superman into a police car, crushes the car into a wad of steel around him, tosses it through the side of a building... then collapses the building on top of him by firing a missile into it... then sets the rubble on fire... then strides through the fire to stomp on top of the rubble pile. Problem is, he's fighting Superman - when Supes breaks out underneath the mecha, his hair isn't even mussed.
Non-fatal example: one episode of Invader Zim had a water balloon fight between the title character and his rival, Dib. While Dib builds a backpack that creates and launches water balloons, Zim created an orbital space station that sucks out all the water from the city, collects it into a balloon that dwarfs satellites, and launches it right onto Dib. The resulting collision causes a tidal wave that devastates the city.
The premise of the '90s cartoon The Bots Master is that an evil, near-future corporation is gradually upgrading all the millions of service robots in the world in preparation for an eventual robotic coup. In one episode, the hero's Bratty Half-Pint sister discovers that they're scheduled to upgrade two lowly lifeguard bots at a nearby beach. Determined to prove herself while her brother's away, she uses their automated base to construct a massive, Normandy-sized armada of mechas and fighter ships to storm the beach, while the shell-shocked villains are left frantically screaming "it's just two lifeguard bots!!"
One episode of The Simpsons has Homer grabbing a cigarette, stomping on it until it's flat, and then unloading a whole mag into it.
"These are the Yakuza. They kill you 16 times before you hit the ground."
"Welcome to Lee Carvallo's Putting Challenge. I am Carvallo. Now, choose a club. (beat) You have chosen a 3-wood. May I suggest a putter? (beat) 3-wood. Now enter the force of your swing. I suggest: feather touch. (beat) You have entered: power drive!"
Metalocalypse. When Dethklok is given the privilege to choose how a group of criminals would be executed, what is their idea? Strap the criminals to missiles, fire said missiles into the sky, then shoot them down with lasers. Naturally, they wrote a song about it.
When Ofdensen and Melmord were fighting over the position of Dethklok's manager by a fencing match. Ofdensen won, stabbing Melmord in the gut and throwing him off a tower. And to really make sure he was dead, Melmord got run over by a train. It was yet another Awesome Moment for CharlesFosterOfdensen.
In one episode of Inhumanoids, the over-the-top fanatical Soviet soldier accompanying the bad guys is asked whether using a particular weapon wouldn't be overkill. He responds, "There is no overkill! There is only kill and no kill!"
In TaleSpin, the official method of execution for the country of Thembria is by firing squad. In this case, the firing squad either uses cannons, or tanks. They also hang you after they shoot you, as Becky finds out in "The Time Bandit". At least you get to choose the type of noose they use.
This is how insane time traveler Chronos in Justice League Unlimited reacts to subordinate Chucko betraying him and giving key information to the Terry McGinnis Batman. Chronos sends Chucko to what is ground zero of a massive extinction event.
Chronos: Do you know what killed the dinosaurs? Well, Chucko does!
A truly hilarious example in The Grim Adventures of Billy & Mandy: Billy's bike is run over by a car, mangling it. Billy says "Well, it still kinda works..." The bike is then crushed by a falling tree, zapped by a UFO's laser cannon, and hit by a meteor... which then grinds itself (and the bike) down into the center of the earth.
The Powerpuff Girls episode "Him Diddle Riddle" has Him presenting riddles of various levels of danger or else the Professor will PAY. Some could result in death, others could result in a missed phone call. One, however, could result in Ms. Keane being dumped into "this vat of boiling sharks". Him may have been bluffing, because as it turned out, the part about the Professor having to "pay" was a joke: it meant "pay full price" for breakfast at a restaurant.
In the My Little Pony: Friendship Is Magic episode "Green Isn't Your Color", Pinkie Pie's method of keeping a secret seems to be as follows: zipping her mouth shut, locking the zipper shut with a key, digging a hole in which she buries the key, building a house on top of the hole, and moving into the house.
In the episode "Feeling Pinkie Keen" a flowerpot, an anvil, a hay cart, and a piano fall on Twilight Sparkle's head in quick succession.
In "Wondebolts Academy" Lightning Dust attempts finish a cloud-clearing exercise by creating a tornado, despite already having a very clear lead on all the other competitors. Said tornado nearly kills somepony.
In an episode of American Dad! Stan kills Principal Lewis' "prison wife" Tracey by sending him off a cliff in his car, shooting him, feeding him to an alligator and turning said gator into skinned suitcases and clothes. And Tracey came back unscathed.
Dale: I used as much ant killer as I needed, and not one 55-gallon drum more.
In the Young Justice: Invasion episode "Satisfaction", Captain Cold attempts to rob a bank. Unfortunately for him, Rocket was having a bridal shower nearby, with Batgirl, Black Canary, Bumblebee, Miss Martian, Wonder Girl, and Zatanna as her guests. Just one of them would be more than enough to take Cold down, yet all 7 of them rush after him! Knowing how hopeless the situation is, he doesn't even attempt to fight back: