In the live action Dudley Do-Right movie in 1999, all of the main characters understand that they live in a corny, formulaic melodrama, and they're perfectly happy about it. Later, the hero and villain begin to deviate from their predetermined roles within the genre, which provokes a severe existential crisis in both men. This is so stressful that Snidely Whiplash returns to his villainous ways, despite knowing in advance that "The Bad Guy" is automatically predestined to failure.
Snidely Whiplash: This is the part of the job I hate the most, the ending. Up until then, being The Bad Guy is the best job in the world.
The entirety of the Scream franchise is based on the characters being Genre Savvy, to the point that they make comments like "I know what happens to the black dude, and I'm getting out of here." Randy Meeks was a veritable fountain of knowledge about how to survive a horror movie until he found a giant Idiot Ball and turned his back to a dangerous area. In fact, most characters who die are the ones who make stupid mistakes. The characters know this, and discuss mistakes that should never be made, such as going off on your own.
In The Faculty, several of the students (being sci-fi fans), realise that the strange goings-on at the school resemble the Invasion of the Body Snatchers. Though they correctly work out that the 'infected' are actually part of a greater 'queen' organism (and what happens should they find and kill it), they fail to realise that the queen is actually The New Girl and not one of the more obvious suspects. The 'queen' even asserts that they should stop resisting her, since this plot ended in them winning even in fiction (the pod people in the aforementioned Body Snatchers). Though Genre Savvy, Casey comes up with a quite amazing conspiracy theory regarding aliens: he asks whether sci-fi itself is a tool for the authorities to inure the public to the existence of aliens, just so nobody would believe it if it really happened. Stokely is unsurprisingly not convinced in the slightest, but thinks it's a cool idea.
Hot Fuzz plays off one of the characters' detailed knowledge of action cop films.
When the characters realize they're in a real space battle, they try to use sensible, real-life tactics, and fight the tendency to act like the characters they play — which backfires, because they're much more effective once they start acting their parts.
In possibly one of the most well-done moments of villain genre savviness ever, once shown the "historical documents", Sarris is the only nonhuman character who realizes that he is dealing with actors who have been mistaken for real explorers. This implies that unlike the Thermians, his own race produces entertainment.
Sarris: How adorable. The actors are going to play war with me!
In Last Action Hero, Danny Madigan, the kid from the real world, having seen so many action movies, knows all the clichés and plot devices when he winds up inside one. Jack Slater, the fictional Hollywood action hero who lives in the movie, refuses to believe him, suffering from Genre Blindness.
Jeepers Creepers has Trish display this a few times. As Darry is climbing down the drain pipe looking for a dead body, Trish tells him, "You know the part in scary movies when somebody does something really stupid, and everybody hates them for it? This is it!" Later, after hitting the Creeper with their car, Darry asks, "Do you think he's dead?" Trish responds, "They never are," before running him over a few more times. It doesn't work, but at least she tried.
Many of the recurring characters in Kevin Smith's films seem to be genre-savvy. One glaring example is Azrael from the film Dogma, who, as his Evil Plan for the destruction of all reality comes together, is asked how he did it and what he needs to do by the imprisoned good guys. Azrael's response:
In Time Bandits, Kevin, at least, knows what's up when they meet Robin Hood. He even tries to explain to the dwarves afterwards that of course Robin was going to hand out the stolen treasure to the poor.
Pretty much the entire point and struggle of Stranger Than Fiction revolves around the lead character (who hears a voice narrating his life) trying to figure out what kind of story he's in. If it's a comedy, he'll live; if it's a tragedy, he'll die. For help he visits a professor of Literature, who asks him bizarre questions like "Are you the King of anything?" and "Do you have magical powers?" His negative responses eliminate fantasy, mythology, historical fiction and other genres in order to find out the type of story he's in.
Both the main characters in Kiss Kiss Bang Bang use their knowledge of the plots of mystery novels to foresee the events which will occur in the movie. At one point there is a false end where the female lead says something along the lines of, "this isn't how it ends, this can't be how it ends. Usually at this point there's a big action sequence where the hero kills a bunch of people for no good reason." Shortly thereafter the hero becomes engaged in a big action scene where he kills a bunch of people.
Dead Snow: The Genre Savvy character tells everyone not to get bitten when he realizes that they're under attack by zombies. One character later saws his own arm off with a chainsaw after being bitten because of this, though it's never actually established whether biting really does lead to zombification.
The brothers have an argument about whether they need rope. Connor thinks that rope is always a Chekhov's Gun, but Murphy tells him that this isn't a movie.
Smecker starts working out the methods the brothers are using when we realizes that the insanity he's seeing at the crime scenes are the results of people doing stuff they see in cheesy action movies.
In Sleuth both characters try to use their knowledge of detective stories to their advantage.
The Hard Way. The Tag-Along Actor warns the Cowboy Cop that the killer will come after him as it's the Third Act. The cop laughs off the warning, as "real criminals stay well away from the police". As the killer he's chasing is not entirely sane, that's exactly what he does.
In Drishyam, Vijay knows how to avoid getting caught by the police because he watches procedurals regularly.
Unbreakable deconstructs this trope horrifically. Elijah takes Genre Savvy too far and sees comic book tropes in the real world - and he's not entirely wrongnote the film implies the real-life people who inspired the tropes - so he causes "accidents" which kill hundreds of people in the hopes of finding a superhero. It ends as he reveals the truth to David and happily describes how he is clearly meant to be the villain of their story, delighted to finally know his purpose.
Elijah: I'm not a mistake! It all makes sense! In a comic, you know how you can tell who the arch-villain's going to be? He's the exact opposite of the hero. And most times they're friends, like you and me!
The Marvel Cinematic Universe version of Spider-Man is a sci-fi and action movie buff and constantly uses tactics the heroes in those films use against his foes.
Spider-Man: You ever see that really old movie, Empire Strikes Back? War Machine: Jesus, Tony, how old is this guy?
Avengers: Infinity War: When Iron Man on-the-spot asks him to formulate a plan that will take out Ebony Maw and save Doctor Strange, Spidey thinks about it for a few seconds and asks Iron Man if he's "ever seen this really old movie, Aliens?" Cut to Iron Man confronting Maw:
Ebony Maw: Your powers are inconsequential compared to mine. Iron Man: Yeah, but the kid's seen more movies. [blasts hole in hull of spaceship, Ebony Maw gets blown out]
Fright Night (1985): The two main characters, a teenage horror film fan and a professional Horror Host, get all of their information on killing zombies from horror films. This is lampshaded in one scene where the horror host asserts that movies have been correct on all points so far, so they can safely assume that other tropes will hold true as well. The 2011 remake notably omits this trope as one of its major revisions.
Watchmen: Just like in the Watchmen graphic novel: Adrian Veidt, aka Ozymandias, declares that he is not a "comic book villain", and therefore had already completed his plan 35 minutes before beginning his Breaking Speech
Luisa Rey: "I promise I'll tell you everything that happened in the morning." Javier Gomez: "Okay, but I hope you realize you just said exactly what every character in any decent mystery says right before they get killed."
The Lost Boys: Egdar and Allen make Sam read vampire comics to help him defend himself from the real vampires in Santa Carla.
The Monster Squad: A group of young monster movie fans fight back an invasion of classic movie monsters using their cinema knowledge.
In You Might Be the Killer, Chuck is a horror movie fan who works at a comic store. The reason Sam calls her is that he figures her knowledge of the horror genre might help him survive the slasher movie situation he finds himself in.
The Dead Don't Die: Ronnie is quick to speculate that zombies are responsible for the recent string of murders, being familiar with them through pop culture. He explains what they are and the standard rules for killing them.