Vegeta: They've broken my body... I've failed in my mission to get the Dragon Balls... I've even lost my tail... But at least, it can't get any worse from here... Ghost Nappa: Vegeeeetaaa... Vegeeeetaaa... Vegeta: W-What? Ghost Nappa:I'm haunting you! Vegeta:NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOooooooooo!
Krillin: We won't ever have to see him again! (Vegeta falls next to Krillin) Krillin: ... alive again. I meant we won't ever have to see him alive again! (naturally, Vegeta is alive)
In Episode 18, Vegeta brags to Goku that besides Freeza he's the most powerful being on the planet. Cue the Ginyu Force showing up.
"That's right. I'm your white mage. And nobody fucks with the white mage." Three guesses as to what happens immediately afterwards.
The frigate officer in the Warhammer 40K fan-film Damnatus — "We have never arrived too late before."
In Smashtasm there is a running gag wherein a character will say: "There's no way that ((insert bad thing)), especially not right now! Super64, being Genre Savvy, tries to invoke this trope when he gets captured, saying:
There's no way I could get out of here. Especially not right now."
The Lord of the Rings metafic epic The Official Fanfiction University of Middle-Earth tackles this in an early chapter, when the heroine spends a day with everything going wrong determinedly resisting the temptation to demand what else could go wrong ("for as everyone know, that is an invitation to get a demonstration of just what else can go wrong. The gods/God/evil forces/whatever you believed in were nothing if not equipped with a sense of irony. It's a vital God-quality, that."), until one thing too many does and she lets it slip. She then yells out that she didn't mean it... to no avail.
Tristan: I sure hope we don't encounter any more intrusive subplots. Jean Claude Magnum: Did somebody say "intrusive subplot"? Tristan: Oh, son of a bitch!
On the blimp:
Doctor: I'm glad I have such a long and villain-free life ahead of me. Melvin: Hi there. Could I get a hug? Dr. Feelgood: A hug? Sure, I don't see why not. (the sounds of chainsaw revving can be heard) Oh my god, it burns, it burns!
In the 26th video of Ultra J Man's Let's PlayI Wanna Be The Guy, he is still angry for a previous crash he had, and he declares "I get to the end, I beat The Guy, and it fucking crashes. That's how it's gonna end!"Guess what happens.
During the same video, Chuggaa points out how stupid it is that an NPC points out a very obvious hazard, wondering how anybody could ever get hit by them. He doesn't even manage to finish the question before he gets hit.
During the outtakes from the third Rival battle: "What the heck was I worried about, it's a freaking Rattata." Said Rattata then uses Quick Attack, gets a critical hit, and kills off his last Pokémon. "WHAT?! WHAT?! WHAT?!"
In Awesomeness Of The Ocarina this trope is inverted and discussed. "Even though Navi tempted fate with the dreaded "It can't get any worse" stock phrase, things actually got better. Link noticed this, but he didn't want to push his luck."
Subverted in episode 45 of Pretty Cure Heavy Metal. After taking a single whiff of a cigarette, Shugo says she doesn't want to get addicted. Guess what? She's remained smoke-free ever since.
Lampshaded in Harry Potter And The Methods Of Rationality during the Stanford Prison Experiment arc. Dumbledore declared himself invincible and an Azkaban guard asks in astonished horror if he really just said that. Her commander says that he can get away with it since not even fate takes Dumbledore seriously anymore.
In A Hero, the second chapter has Dalek Sec watching Homura battle Walpurgisnacht from afar, and concluding that the Witch isn't looking his way, and wouldn't attack him. Fortunately, Sec's Genre Savvy enough to realize what he just did, which gives him just enough time to learn that a horde of familiars are heading his way.
This is referenced in The Man With No Name while some characters are infiltrating the enemy stronghold. It ultimately ends up subverted, however; despite the Doctor's expectations, nothing of the sort happens.
Inara: They seem to be expecting an auditor.
The Doctor: Good. No one will get too fussed when we go about asking nosy questions then.
Inara: As long as the real auditors don't show up, we should be alright.
In the Katawa Shoujo fic Lilly Epilogue Family Matters, Hisao narrates that "Considering that just one year ago I probably felt like the most pathetic sap on the planet, things are definitely looking up. Everything just feels right with the world." In the next scene, he finds out that his girlfriend Lilly's parents are coming to visit, prompting him to think "Ohfuck".
Mei: You know, this kind of creepy tunnel place with a load of dead bodies in it – well, dead robots, but it's the same sort of thing – you'd expect them to, like, get up and start attacking when someone poked one. Heidi: Will you shut up? You don't say stuff like that on a mission, do you want to make us all paranoid and jumpy?