The Prolecto series, at Episode Two and later, falls into this, and at first balances hilarity with reality, but moves towards non-humorous reality later on. For instance, at the end of the first one, they decide to start converting everyone! At the beginning of the second one... They're in prison for, amongst other things, public nudity!
Doctor Horrible's Sing-Along Blog: Near the beginning of Act II, Dr. Horrible gloats about his unstoppable plan to commit a heist using his Freeze Ray. Cue Gilligan Cut and a bruised Dr. Horrible explaining how he needs to be careful about what he says on his blog because both Captain Hammer and the LAPD watch it.
The entire premise of the Smosh videos, "If X Were Real".
We're Alive: Angel attempts to use a broken zip line to repel down from the roof of the collapsing Tower, barehanded. The result is he tears up his hands, lands next to the remains of a tanker truck filled with burning diesel fuel, and is left barely clinging to life but slowly dying from his injuries. It's made very clear his injuries would have killed him if Scratch hadn't given him a terminal case of lead poisoning first.
Sonny Gets Mad Scienced; a Genre Savvy geek gets kidnapped by a mad scientist for use in horrible experiments that have killed — or worse — every one of his predecessors. He's going to use his trope knowledge to break free and save the day before the experiment, right? ... Right?
In this Dorkly video, Rusty challenges some Team Rocket goons to a fight. Team Rocket just shoots Rusty's Pokemon.
Ensues in Worm when a member of the ABB tries to use a sword to intimidate and fight Skitter, who controls a giant swarm of insects.
Played for Laughs with one of 1d4chan's home brewed Space Marine chapters, The Reasonable Marines. They act like normal soldiers focusing on stealth and efficiency, trying to avoid combat unless needed, and actually trying to be diplomatic with aliens instead of shooting them on sight. The joke is they are the only sane group in a universe filled with nothing but Rule of Cool and Crazy Awesome lunatics.
In the What If? entry "Spent Fuel Pool" Randall Munroe explores the physics-based answer to how safe it is to swim in a nuclear reactor's spent fuel pool. Because water is a good insulator against radioactivity it's pretty safe if you stay away from the casks. He then poses the question to a friend who works at a research reactor.
Randall's friend: In our reactor? You’d die pretty quickly, before reaching the water, from gunshot wounds.
ASDF Movie: In the second episode, a bear named Desmond is briefly seen, wondering how he got on the moon. In the seventh episode, we see him again. He's dead. No air on the moon, you know.
In the fourth episode, aliens attack. A onlooker heroically yells, "Throw! The! CHEESE!" He throws a ton of cheese... and it all just bounces off the spaceship.
The story of the first owners of SCP-1958. All but too excited to have a bus that can travel in space, they set off to colonize the stars...neglecting the fact that it still goes at the same speed of a regular bus, and their destination was lightyears away. They realized it when, after two months of travel with the crew dwindled and nearly starved to death, they realized they barely made it to the Moon.
One of the general themes of SCP is pointing out the horrific consequences of characters and plot devices with fantastic abilities, powers, or properties. A good example is the Keter-class SCP 871... self-replicating cakes.
Siberys shows what happens if you quickly cobble together a vaccine/drug and use it without proper testing and/or followup. The vaccine he took works as intended but he dies from the complications several years later.
Chris MacLean shows what the stress of being responsible for someone's death as well as keeping a deep secret for decades can do. He becomes an alcoholic and later dies in an alcohol related accident.
Quackerjack attempts to do a Sadistic Choice in episode 6 of Ducktalez with a pair of gondolas as a reference to The Dark Knight. However, the criminals blow up the gondola with the civilians 3 seconds in.
This take on the Jeff The Killer creepypasta shows about how well a teenager with grievous recently self-inflicted facial injuries like massive incisions to the face and burned eyelids would fare as a killer. He fails to kill his last two intended victims, and his wounds become severely infected, resulting in sepsis and death.
Mario Kart 8 is Great starts with the Mario and friends getting ready to race underwater. However, as soon as the green light flashes, they have already drowned and their bodies are shown floating on the surface.
The PEFE Founders took down the corrupt corporation Pokéfutures Inc., who also happened to be the lynchpin of Angela's economy. This resulted in the Angelan economy going into freefall, and had the Founders not took the deal to take all their assets they would've ended up in prison.
Raise loads of sapient beings for use in competition and basically rejecting the rest for one or two perfect mons? Be prepared for a lot of issues regarding self-worth.
Verax may have done a Heel-Face Turn, but that doesn't mean the J-Team members who he's tried to kill before are going to like having him around.
Daisy and Pentigan got together due to their adventures fighting Glitch Pokémon, but once that was over, they found that apart from a shared horrific experience they didn't really have anything else in common and broke up.
The J-Team causing property damage to the places they stayed at caused many hotels to ban them from staying there.
Psychological issues take time to fix and may never fully go away.
During the Hoenn arc Tagg decides to have his mons destroy a perfectly legal Neo-Magma machine to stop them from destroying a beach and is forced to retreat by them calling the cops as that's vandalism.