When it comes to pet peeves from movies, I really only have two major turn-offs. The first are boner gags. Pretty self-explanatory. Just a perfunctory sight-gag lacking in any modicum of wit or originality. I don't require all of my movie comedy to be refined or effervescent like Noël Coward (or relentlessly ingenious à la The Marx Brothers) but even Blazing Saddles (which managed to throw in everything but the kitchen sink) left out the boner gag. Nowadays, as we can get away with a lot more, it would seem the boner in the pants routine is a bit more in vogue. Just ask Robert De Niro who submitted to one in 2010's Little Fockers.
Step Brothers (quite hilarious actually) opted for the use of a prosthetic ball-sack getting rubbed on a drum set (as a stand-in for Will Ferrell's actual testicles) in lieu of a hackneyed hard-on joke. A wise move, unlike the puerile erection antic in the first Anchorman. At least Walk Hard caught us off guard with real male genitalia. I'm not really sure what to call my other film-watching bugaboo as I've never been able to find a specific mention of it anywhere. But I despise it far more than the sight of Steve Carell sporting a fake boner in The 40-Year Old Virgin.
For me, this is as clichéd as it gets, and a real deal-breaker. I hate it when a film presents us with a character who has written a book, manuscript or screenplay in the course of the film which is revealed in the end to be the name of the actual film we are watching. This somehow fits into the realm of metafilmic principles even though I can't think of an exact phrase for it. One of the first films I remember noticing it in was John Hughes' She's Having a Baby. The character played by Kevin Bacon is a young advertising exec who finally pens that great American novel he's always had welled up inside him.
Of course the final shot of the movie is the title page of his manuscript when it's revealed that he's called it (yep) "She's Having a Baby". How cute and totally unoriginal. The worst part is, the film really has nothing to do with Bacon's character being a writer. Hughes couldn't come up with something else to call his story-within-the-story? The same triviality was used recently in Wes Anderson's The Grand Budapest Hotel. The book that starts the narrative ball rolling is revealed to be called (you guessed it) "The Grand Budapest Hotel". I know it might not sound like a major gripe, but man, this just drives me up the wall.
The same self-referential device is used in Baz Luhrmann's The Great Gatsby (2013). What is perhaps more stunning about this particular usage is no one is actually writing anything in Fitzgerald's source novel (or Luhrmann's film; until at the end it is revealed that the narrator has fashioned a book of the experiences we've just seen called "Gatsby" which he adjusts by hand adding "The Great"). The book that Billy Crystal's character writes in Throw Momma From the Train (one of my favorite comedies) also bears the film's title at the end, but at least that film had something to say about the craft (and business) of writing.
Incidentally, when the movie that's playing within Blazing Saddles is revealed to be called Blazing Saddles (or a similar meta-movie gag in Mel Brooks' Spaceballs) I don't have a problem with it. It's only when the device is applied to a fictional written work. I'd pause before even referring to this as an actual literary device (such as a nested story). It's more like an oft-repeated instance of lazy scriptwriting that's meant to be a clever wink and a nod to the film's audience. It mostly just makes me want to puke.