Contains spoilers obviously.
Terminator Salvation (2009)
The fact that amnesiac Marcus Wright (Sam Worthington) is actually a terminator who’s been programmed to think he’s human could’ve made for an interesting little reveal in McG’s otherwise quite disappointing sequel if it wasn’t shown to us in the trailer first.
It effectively eliminates any of the mystery which the film attempts to build up around the character so that all of the time spent doing that feels annoyingly pointless and like it could’ve been put to more effective use developing some of the other bland players instead.
Terminator Genisys (2015)
It’s almost as if the marketing team for Genisys saw the Salvation trailer's mistake and thought “hold my beer” because the decision to reveal that mankind’s saviour John Connor (Jason Clarke) is now a terminator constitutes one of the very worst offences on this list.
A moment which could’ve certainly provided one hell of a twist and injected a bit of refreshing originality into an increasingly stale series is rendered completely ineffective and left to be just another plot point in this muddled action film.
The Island (2005)
Transformers director Michael Bay isn’t exactly known for his subtly but his 2005 sci-fi action thriller starring Ewan McGregor and Scarlett Johansson might’ve fared a bit better at the box office if it hadn’t fully explained away everything in its trailer.
When you already know that all of those populating Dr Merrick’s (Sean Bean) futuristic compound are clones, what could’ve been a nicely tense first half with a wonderfully eerie atmosphere becomes just a dull precursor to the tedious action sequences.
The Dream House (2011)
If the awful critical reviews, Dream House currently stands at a lowly 6% on Rotten Tomatoes, weren’t enough to put you off My Left Foot director Jim Sheridan’s excruciatingly slow-paced horror film then the incredibly spoiler-filled trailer definitely is.
The only thing the film has going for it, what happened with Peter Ward and the murder of his family, is ruined when we learn writer Will (Daniel Craig) is him, meaning all that we’ve seen of his happy life is clearly a fantasy and there’s no longer any need to watch the film.
Batman Vs Superman: Dawn of Justice (2016)
Although the trailer’s reveal that Batman (Ben Affleck) and Superman (Henry Cavill) eventually unite was hardly a spoiler, its showing of surprise second villain Doomsday and Wonder Woman’s (Gal Gadot) first ever live-action costumed appearance was definitely a bad move.
Announcing the fact that the trio have to face-off against one of Superman’s deadliest foes cheapens the titular clash and while the Wonder Woman scene is still pretty exciting when you see it, think how epic it would’ve been as a surprise.
Although you couldn’t endlessly rewatch a trailer on YouTube in 1976 like you can today, that’s still no excuse for Brian De Palma’s otherwise excellent Academy-Award nominated horror film to spoil the majority of its iconic third act in the trailer.
Showing that intense sequence of events in which the tormented Carrie (Sissy Spacek) finally snaps and unleashes her now uncontrollable telekinetic fury at prom ruins the film's brilliantly well-crafted sense of dark foreboding and robs it of any real shock it might’ve contained.
The Last House on the Left (2009)
Nobody is paying to watch this glossy remake of horror icon’s Wes Craven’s 1972 unflinchingly brutal revenge flick for the quality of the acting or complex storyline which makes the decision to include footage of all the gruesome kills in the trailer absolutely baffling.
No gore is shown, but you very clearly see the ways in which vengeful parents Emma (Monica Potter) and John (Tony Goldwyn) methodically dispatch of the sadistic gang who’re sheltering their home via stabbing, electrocution and for leader Krug (Garrent Dillahunt) total paralysis and the placing of his head in a microwave.
Dutch director Jan de Bont, who’s also responsible for another enjoyably cheesy 90s action film Twister, set the US box office alight back in 1994 with this energetic popcorn thriller which earnt back way more than its original $30 million budget.
But the film is really only successful at building a tense and hugely suspenseful atmosphere if you haven’t seen the trailer which unfortunately contains an explicit shot of the civilians who’re originally trapped on the bus watching from a safe distance as it explodes.
Funny People (2009)
The trailer for what is easily Adam Sandler’s best film of the last ten years works to remove a lot of the appeal of seeing him actually use his comedic talent by literally spelling out the whole plot beat-by-beat.
Not only does it reveal that his depressed comedian George recovers from leukemia but also shows all of the ups and downs of his friendship with Ira (Seth Rogen) and scheme to win back ex-fiance Laura (Leslie Mann) so you feel like you’ve already seen the film.
Kingsman: The Golden Circle (2017)
Director Matthew Vaughn has himself expressed his annoyance over the marketing team’s decision to spoil the fact that Colin Firth’s super spy Harry Hart is alive in the explosive trailer for the sequel to his ultra-violent and hilariously funny James Bond spoof.
It lessens the surprisingly affecting emotional impact of the last film considerably, especially as Hart’s supposed murder at the hands of eccentric billionaire Valentine (Samuel L. Jackson) was the motivation his formerly directionless protégé Eggsy (Taron Egerton) needed to become a proper Kingsman agent.