100 Feet: After another day of the protagonist being terrorized by the ghost of her abusive husband, another character comes over to "comfort" her. While they're having sex, she sees the ghost hovering above them, but it fades away harmlessly. She figures this is the last she's seen of the ghost, seeing as how by this point, she's gotten rid of seemingly all of his possessions. But when she and the other character awaken the next morning and she goes to look out the window at the beautiful day outside, the camera pans to the wedding ring she's still wearing, and character she just slept with is suddenly knocked across the room and given a lengthy and fatal No-Holds-Barred Beatdown by the ghost as she's forced to watch.
1408: The Hope Spot given to both Mike and the viewer subverts a couple other tropes. Fairly late into the movie, we're inclined to believe that it was All Just a Dream. He starts to turn his life around, and starts confronting and repairing all of his life's problems that the room threw in his face. All in all a happy ending, right? Nope. Still in the room.
Alien Abduction (2014) offers us one as Jillian and Riley finally escape from the woods in the morning, having apparently eluded the aliens that kidnapped the rest of their family, and manage to flag down a highway patrolman. Unfortunately, as the cop is calling for an ambulance for the two, Riley's camera starts glitching, and the aliens show up one last time to grab the two (and possibly the cop as well).
In Annie (2014), Annie is supposedly reunited with her real parents, only to find out they're dupes. By the time she figures this out, she's locked in their car.
Avengers: Age of Ultron: Ultron has captured Black Widow and is holding her prisoner wile gloating all the way. All the sudden he's ripped apart by something! Oh wait, it's just Ultron doing it to himself, showing off his ability to inhabit multiple bodies.
Battle Royale: This movie has Shinji Mimura's team succeed in hacking into the government's computers, temporarily deactivate the collars, and load up a truck with enough home-made explosives to blow up the school that serves as the government headquarters. They're about to start their attack when Kiriyama shows up and kills them all. However, Mimura is able to set off the explosives, blinding Kiriyama just as the other main characters show up.
Black Water: This movie is full of this. Every time they make some attempt at escape, it either turns out to be fruitless, or they have to get in the water and the croc attacks someone. Then in the third act, Lee leaves the injured Grace in the relative safety of the tree so she can have another go at getting the boat. She actually ends up taking a gun off a previous victim and shooting the crocodile dead. She then makes her way back to the tree, calling out to her sister that she "did it," and she's coming and they can go home... Then she gets back to the tree to discover Grace died from her wounds while Lee was away. Ouch.
Subverted in Blankman: The Man Child superhero, on a crusade to defeat the crime kingpin Michael "The Suit" Minelli, has created a robot sidekick and takes it along on his big mission. At one point it appears as if the clunky little droid has survived been blown up by a trap set by Minelli's thugs, but then it only manages to roll a few steps before splitting in two and falling apart. Blankman reacts with an anguished Big "NO!" that lasts for several seconds - and then immediately screams, "Minelli, you're goin' down!" (And he does.)
Brazil: At the end, Sam Lowry is restrained to a chair in a large, empty cylindrical room in the Ministry, to be tortured. However, before his torture begins, members of the resistance break into the Ministry. The resistance rescues Sam and blows up the Ministry building as they flee. Sam and Jill drive away from the city together, and they are pictured living in a trailer in the countryside. However, It is then revealed that Sam has gone completely insane and is catatonic in the torture chair, humming a happy tune. Cheerful!
Buried: When the protagonist gets the phone call that an insurgent revealed the location of a buried hostage, he calls his wife on the phone to give her the miraculous news, only to find out a few minutes later that his rescuers were informed of an entirely different hostage burial site. And all this is happening as The protagonist's coffin is quickly filling up with sand. The film ends when the coffin fills up completely, and the screen goes black.
Carlito's Way: Has a cruel one at the ending. It looks like Carlito has gotten away from his enemies and he'll finally escape to a peaceful life with his girlfriend, but right before he makes it into the departing train he is shot by Benny Blanco.
Cloverfield: The protagonists are in a military helicopter, being evacuated. They look out the window and watch as the giant monster is bombed repeatedly. When the monster doesn't seem to be moving in the cloud of smoke, everybody cheers... and then, not only does it survive, it reveals it presence by leaping out of the dust and smoke, grabbing the helicopter, and dragging everybody down to the ground where they are all killed as Manhattan is bombed off the map.
Collateral: About two-thirds of the way through, Detective Fanning pulls Max away from a nightclub firefight to safety. He believes his story, looks like he's going to help solve all of Max's woes...then is gunned down by Vincent without a pause.
And then Joker and his gang got imprisoned, Gordon is actually alive, and Harvey and Rachel are set to ride off into the sunset... Or so you think.
Harvey has an In-Universe one shortly afterwards... As he's lying in a hospital bed recovering from a bomb blast, he's convinced that Rachel is dead. Then he finds the "lucky" coin (you make your own luck, it has two heads) he gave to her the last time he saw her alive, left on his bedside and apparently unmarred. He turns it over... and sees it's charred on the back.
Gets a Lampshade Hanging and Invoked Trope by Bane in The Dark Knight Rises, who believes that true despair requires giving others a glint of hope. In his case, this was the light coming from the roof in the Hellhole Prison he lived in. In Gotham's case, it's giving the people the impression that the city can be freed from the corruption of the elite by using a nuke as a threat, all the while intending to have the bomb blow everyone up no matter what.
An extremely cruel one in Das Boot, as the submarine tries to sneak through the Straits of Gibraltar and is damaged by Allied aircraft, sinking to the bottom. The crew manage to raise her and repair her before their oxygen runs out, and the captain tells them to run for La Rochelle. Sweeping, intense music plays as the submarine makes it's escape, with the captain yelling to the distant British "not yet, kameraden, not yet!". Then, after they arrive at La Rochelle, safe after their long and perilous voyage, an Allied aircraft strafes the dock and kills most of the crew and main cast.
Where in the end, one of the ladies makes it alive out of the cave, getting out through a narrow gap, runs to her car, drives away. Then it turns out she was hallucinating, and is still sitting in the cave, crazy and catatonic. As the camera pulls away, we hear the crawlers screeching.
This ending is the original British version. The American release cuts The Reveal that Sarah was hallucinating her escape, making seem like she got out of the cave alive. The sequel pretends that the American release was real.
Drag Me to Hell: Christina digs up the Gypsy lady's corpse and passes the curse back to her by shoving an envelope containing the cursed button into her mouth. It's over, right? Well, it turns out that the envelope that Christina buried the Gypsy woman with didn't contain the button at all, but rather, her boyfriend's rare coin. She still technically owned the button, which meant that, since three days have passed, she has to go to Hell. Got to love Sam Raimi's sense of humor.
In Elysium a lone ship manages to make it past and evade Kruger's missiles but are apprehended upon landing. One of the immigrants from the shuttle that manages to make it to Elysium manages to get to a Med Pod and heal her daughter's leg enabling her to walk. Only to get tazed and arrested immediately afterwards. All things considered, though, that woman got exactly what she came for. It's highly unlikely she expected to stay there.
Everest (2015): Base Camp arranges to send fresh oxygen up to Rob, who is stranded near the summit. Unfortunately his rescuers are forced to turn back before they can reach him when the weather takes a bad turn.
The Evil: The force that keeps characters trapped lets one them escape the Vargas house, only to turn the ground beneath him into quicksand couple feet away.
Ex Machina: Just when you think Ava's dressing herself in skin and a nice dress and is now going to go surprise Caleb with it and run away with him - she doesn't. Instead she leaves him trapped in Nathan's compound - presumably till he eventually dies.
Final Destination: The entire plot of this series revolves around the main characters narrowly avoiding death and being killed off as fate "catches up with them". Five films of splat as plot....
Fish Story: In one sequence, the Champion of Justice has been beaten down and tied up, but manages to free himself. He rises, and begins the Slow Walk towards where the villains are standing. A couple of spectators look on in awe as the music swells...and then stops, and the flinch as a series of gunshots end the sequence. Subverted Trope On the other hand, in the end we see the full scene, as the Champion dodges bullets, lays down the law, and saves everyone.
Fist of Legend: Jet Li's best movie, has a pretty cool one. At one point, the Big Bad has a cut above his eye, and Li waits till a drop of blood is about to drip into his eye, then attacks... but... ouch.
The Flintstones: The Live-Action Adaptation has one when the mob is about to hang Fred for firing them from their jobs as Barney comes in when he admits that he's the reason Fred has the job. The mob then decides to hang both of them.
Funny Games is filled with situations where you feel hopeful for the victims, like something would turn in their favor, and each time that door was slammed shut.
The son gets hold of a shotgun and shoots at one of the villains. Too bad the rifle wasn't loaded.
The killers suddenly leave, giving the husband and wife some glimmer of hope that they'll survive. Paul later lampshades that this was necessary for traditional plot structure.
The wife manages to grab the killers' gun and shoot one of them. It looks like the other killer loses his mind when he tries to undo the event with a remote control, but it actually works. The scene rewinds and this time the killers hang onto the gun.
When the wife is tied up in the boat and they are about to push her into the lake, she spots the knife her son had left there earlier and for a few moments it looks like she might actually be able to get away. However, one of the killers notices it too and grabs it before she has a chance to take it.
Used in this film. At first, it looks like King Ghidorah (Who is ironically the good guy in the movie while Godzilla is the Big Bad) has the upper hand against Godzilla. However, it turns out that Godzilla has simply been absorbing all of his attacks and then fires a super-charged Thermonuclear Breath attack at Ghidorah causing him to explode.
A more minor example: A girl who survived an earlier rampage lies trapped in a hospital bed (due to having a leg in traction) and can only scream/sob in horror as Godzilla heads straight for the hospital...and passes harmlessly right by it. The poor girl quickly composes herself and breathes a sigh of relief. Unfortunately for her, his tail has other ideas.
During the monsters' arrival at San Francisco, a MUTO unleashes an EMP. Elle sees a trooper parachuting in and thinks help is on the way... until it turns out that the "trooper" was a pilot who had ejected from his fighter, as planes start dropping out of the sky.
Another one occurs when Lt. Brody manages to start to get the boat with the nuke on it going into the sea, only to then have it die when the female MUTO shows up.
GoldenEye: Boris Grishenko has somehow survived a massive gunfight, complete with explosions, that has killed everyone around him. He takes a moment to celebrate his good fortune with his Catch Phrase ("I am INVINCIBLE!")... and a vat of liquid nitrogen bursts right behind him, covering him and freezing him to death instantly.
In Goodnight Mommy, the mother manages to work the tape gag off of her mouth... right after the Red Cross workers left. Then, later, when untied, she manages to run downstairs and heads for an open doorway... only to hit a tripwire and knock herself out.
At the end of the Holocaust movie The Grey Zone, after the Jewish Sonderkommandos have all been killed, it almost seems like Mussfeld is going to let the little girl live and run away to freedom. As she runs towards the gates, he nonchalantly grabs his pistol and shoots her in back of the head.
Parodied, when Phil — driven to despair by the "Groundhog Day" Loop he's trapped in — kidnaps the titular groundhog and drives with it over the edge of a quarry in front of his cameraman and producer:
[The truck smashes into the bottom of the quarry and lies still]
Larry: [Weakly] He... might be okay.
[The truck explodes]
Larry: Well... no. Probably not now.
A curious Inverted Trope is also presented at the end; after a day in which Phil has proved himself to be a new man and has finally won over Rita, the scene cuts to the same shot of Phil, lying in bed at 6:00AM with Sonny and Cher's "I Got You Babe" playing, suggesting that he still hasn't managed to break the loop. Then, after the song, the DJs begin a different conversation, and Rita leans over him and turns the radio off...
"I got you babe" does start at a differant part in the song on Feb 3. it's done much more straight in the "Christmas Every Day" version, in which the kid wakes up on Dec 26, to the EXACT same rendition of "Jingle Bells", at the EXACT same point in the song, and hears his little sister exclaim "Santa came! Santa Came!" which turns out to be the rest of the family watching a tape of the day before.
Hellraiser: Inferno: After Pinhead informs Joseph about how his flesh destroyed his spirit and Joseph's evil side kills him, Joseph wakes up in the motel again with the hooker still alive. For a short while it seems like all is well and Pinhead just taught Joseph a lesson to better himself, but the hooker is again murdered and Joseph's fate dawns on him.
The Hobbit: The Desolation of Smaug: it seems the greedy Smaug is finally willing to give Bilbo the Arkenstone, so he can finally see Thorin's greed drive him to madness. Unfortunately, the worm got tired of playing riddles and immediately plans to kill Bilbo Baggins.
The Hunger Games: Invoked by Haymitch, convincing Seneca to change the Game's rules. "Give them something to root for: young love." This backfires horribly for Seneca.
A very cruel one in Kanal, set during the Warsaw Uprising of 1944. Daisy is escorting/dragging the wounded Korab through the maze of the Warsaw sewer system. Finally they get to a drain, with Daisy sobbing with relief as she pulls Korab around a corner—only to find that the drain's exit is barred.
Kung Pow! Enter the Fist does this hilariously. After being captured by a tiny net and freeing himself, The Chosen One runs back to find Master Tang, Ling, Wimp Lo and the dog dying or dead. Then, he finds out that Ling is alive, followed by the dog. He goes to check on Wimp Lo, who... isn't. And completely forgets about Master Tang, who is last seen having his body eaten by vultures in the post-credits scene while still alive.
Little Sweetheart: The final shot is of Elizabeth, who, defying all logic, seeing as she's a 9-year-old who took two bullets (one in the arm and one in the chest) and was face down in the water for several minutes at least. The OCEAN water.
Live Free or Die Hard: Has a double one right near the ending. John McClane bursts in on Big Bad Thomas Gabriel to kill him and then rescue his hostage daughter and his ally Matt Farrell. Suddenly one of the Gabirel's goons comes from behind and is able to shoot him, winging his shoulder. Then as the injured McClane crawls for cover, said goon that shot him takes Lucy at gunpoint, but she's able to break free from his grip and kick his gun over to her father... but then Gabriel is able to stop it. Although things do turn out good in the end, it does initially throw one for a loop on the first viewing.
The first film opens with one, as the Last Alliance has routed the orcs defending Mount Doom and are moving in for the kill...then Sauron himself comes out, dressed in full body armor and wielding a mace large enough to send elves flying by the dozen with each swing.
In 'The Two Towers', when the Helm's Deep siege is, while bloody for both sides, still going in favor of the defenders despite the odds against them. Théoden even asks, "Is this all you can conjure, Saruman?" Of course, a short time later, a gunpowder explosive blows a massive hole in the wall, and things begin to proceed as well as you'd expect.
Then there are a few in Return of the King. After the counter-charge by the horsemen under King Théoden successfully routs the much-larger orc army, and the king gives a shout of victory, we can hear the distant rumble of thunder, followed closely by a bizarre bellowing sound. The thunder continues, almost as if it's footsteps...cue entrance of two dozen Mûmakil, aka several story tall war elephants, or, more simply, Sauron's answer to heavy cavalry.
Shortly afterward, Théoden organizes a charge against the Mûmakil, the triumphant orchestra music reaches its crescendo as the two lines meet...and then suddenly ends as the first cluster of riders are smashed into the air by the lead Mûmak's tusks. Several more are stomped to death or simply swept aside. It's as though the orchestra fled the battlefield when they realized what an immensely bad idea charging the Mûmakil was.
Later in that battle, the tide is turning as the Mûmakil begin to fall. Then...the Witch-King shows up.
The Matrix Trilogy seems particularly fond of this trope:
The subway fight between Neo and Agent Smith in the first film has no less than three Hope Spots. The first is when Neo opens the fight with a surprisingly solid start by smashing Smith's sunglasses and visibly pissing the latter off — before getting punched across the room and coughing blood all over the floor. But he gets up, does an Ass Kicking Pose, and starts to completely turn the tables on Smith — before ending up on the receiving end of Smith's Spam Attack. Finally, he barely escapes Smith's chokehold and leaves him up to get run over by the train ("My name... is NEO!") — and Smith simply possesses a new body that's on the train and strolls out to face Neo again. Neo understandably decides to just haul ass out of there.
During the first Smith fight, Neo basically starts off easily smacking around the initial half-dozen Smiths but starts to get overwhelmed when they call in reinforcements. So he looks around and opts to rip a large metal pole out of the ground, and after doing his Ass Kicking Pose with triumphant music blaring in the background, he resumes violently thrashing around the crowd of now several dozen Smiths. But then they call in more Smiths for help, and the pole ends up being the one thing holding the massive swarm at bay. Then of course he loses it and they promptly pile on top of him.
Misery: Famous one occurs near the end: After spending near the entire movie attempting to track down Paul Sheldon after his disappearance, the sheriff finally discovers him at Annie Wilkes' home. So, Big Damn Heroes moment and Paul will finally be saved by the guy, right? Well, it would have been... if Annie didn't then immediately kill the sheriff, dashing Paul's first sign of rescue in months...
Another example happens between Annie and Paul. After Paul found a way to sneak out of the guest room and learned what a truly evil woman Annie Wilkes was, he comes up with a plan to free himself by stealing a knife from the kitchen and hiding it under his bed. Assuming that Annie was unaware of his ability to sneak out, Paul would surprise her in the morning and free himself of her cruelty. Later that night, Paul wakes up terrified to see Annie standing above him and making it clear that she knows. And what was suppose to be the morning Paul freed himself, turns out to be one of the most terrifying of his life as he watches helplessly while Annie uses a sledgehammer to break both his feet so he can't sneak out of the room anymore.
Another instance is when he manages to sneak some painkillers into her wine during their dinner. She drinks, but then drops it by accident.
Mystery Team: The team thinks they have the case all wrapped up.... then they find Leroy and Destiny dead at the lumberyard, and suddenly none of their theories make sense.
Necronomicon (1993): A female cop looking for her kidnapped colleague is lured into an ancient cavern by two bat-people disguised as humans, as their brethren need her brains to procreate. After praying to God for help and promising to turn her life around, she wakes up from a coma in the hospital with her parents (who resemble the two people from the cave) besides her, who tell her that she's pregnant. But no, she's still in the cave and she's carrying one of the bat-things inside her.
Freddy Krueger loves giving his enemies hope spots in the movies: his usual method is to let the heroes think they're actually hurting him, and then shrugs off his injuries with a laugh as soon as they let their guard down. Among others there's Will, whose dream-powers as a wizard seem to be working against Freddy until he gets within striking range; Kincaid, whose superstrength sends Freddy flying until he simply adjusts his own strength to match; Kristen, who seems to take control of her dreams via lucid dreaming and change it into a pleasant summer beach before Freddy turns it back into a nightmare; and Alice, who suffers two of them in two different movies as her attempts to fight Freddy seem to be intimidating him, until he smiles, waves his hand and undoes all the damage.
He even does it to fellow horror villain Jason Voorhees in their dream-world fight in Freddy vs. Jason. When Jason manages to hack off Freddy's arm with a machete, Freddy gives an exaggerated "oh no, not my arm!" And then, after a beat, he simply conjures up a new arm.
The Reveal in the original Friday the 13th (1980) is preceded by one. An old friend of the Christys (the family of the guy opening the camp) arrives at the scene to find a terrified Final Girl and all seems to go well. Unfortunately, that family friend is Pamela Voorhees, Jason's mother and the real killer of the film.
Night Of Dark Shadows: Quentin has finally managed to shake off his past life as Charles Collins for good, chosen his wife and his friends over Angelique, and Carlotta Drake dies, apparently ending the cycle of reincarnation and death that curses both her and Quentin. Then it's revealed that Quentin is also keeping the curse alive, and when he stops back by the house for the last time just to pick up his supplies, he falls to James one last time, adopting his scar and his limp, his wife presumably dying moments after the end of the film, while his friends die off camera.
Night of the Living Dead (1968): There's an absolutely brutal one at the end. Ben is the only character who has lived through to the end of the night, by being calmer, smarter and all-around more badass than the other survivors. It's morning, and the police and military are systematically killing the zombies. They reach the house where he's staying, Ben looks out of the window, and they shoot him in the head and move on without even a word of dialogue.
The Jerkass Mr. Cooper gets one in the 1990 remake when Barbara and the redneck hunting party return to the farmhouse in the morning. After shooting the undead Ben, the rednecks go to search the farmhouse. Alone, Barbara receives a Jump Scare: Cooper is alive and has come down from the attic, where he was hiding. "You came back," he says. Whereupon Barbara shoots him between the eyes.
PCU: It looks like the party has raised enough money, but it was a trap, where the student body would file complaints over the party.
The Perfect Storm: Where right near the end, the main characters see the calm with sunlight shining towards them. They pass through the eye and then... cue more strong waves that capsize the boat.
Pitch Black: The crash survivors are stranded on a desert world with three suns. Searching for water, they eventually find some trees on a hill on the horizon. Yay, right? Sadly, the 'trees' are the skeletal fins of a giant space beastie... and beyond the hill, there's a canyon full of such skeletons. Imam gasps "What could have killed so many great beasts?"
Le Pull-over rouge (The Red Sweater): Twenty-one-year-old Christian Ranucci is sentenced to death for murder on very, very circumstantial evidence. After exhausting his appeals, his only hope of escaping the guillotine is a pardon from the president of France. Cut to the radio issuing the news of Ranucci's pardon, his mother and lawyers celebrating with champagne, and a prison guard rushing in and saying, "Hey, little one! There it is, you're pardoned!" causing Ranucci to smile joyfully. Only, it's a hoax—and Ranucci is dragged from his cell at four in the morning the next day to be executed. Also Truth in Television.
Quintet has one early in the film. Vivia has been shown to be pregnant, perhaps the last pregnancy in the human species. And then she's killed as collateral damage in the bombing of someone she'd first met less than an hour earlier.
Recorded Live: Mr. Aaines is pursued by sentient film hungry for human flesh. He finds a magnet in a box labelled "Fun With Science" and it works in repelling the film. He then puts the magnet down as he tries to open a window to make an escape. This costs Mr. Aaines his life.
Resident Evil: After the survivors obtain the T-virus antidote, it looks like they'll be able to save Rain Ocampo and themselves and get away. Then the Licker attacks and kills Kaplan, Rain turns into a zombie and has to be killed, and Matt's wound starts to fester and it becomes clear he's infected with the T-virus. As Alice is about to inject Matt with the antidote, Umbrella personnel break in and separate them before she can do so. Then it gets worse.
Revolution (1985): The Continental Army looked like it was going to turn the tide in New York City. Unfortunately, the British drove them out of New York and it looked like the British had won.
Has this at the ending of the film. Right after Samara Morgan's body is found you think everything is done and all is safe. However, the Creepy Child informs his mother, the main character, that "she never sleeps." The main character's male companion soon ends up dead because of Samara and they figure out that the only way to stay alive is if they make a copy of the video tape and spread it around. Talk about a cheerful flick.
This also happens in the Japanese film and the original novel, except without the handy foreshadowing. You're completely blindsided by things not turning out well.
During the Normandy Landing sequence, a bullet hits the edge of a soldier's helmet, narrowly missing his skull. Astonished, he removes his helmet and gapes wonderingly at the holes ... and then he gets shot in the head.
Somewhere in the same battle, a team of medics manages to stabilize a wounded soldier's condition in the middle of the fighting. As soon as they finish and it looks like he'll live, a bullet goes through his helmet and into his brain. The medics, not surprisingly, are pissed off at the Germans.
In Saw, Zep is about to shoot Dr. Gordon when Adam suddenly wakes up, trips him, then crushes his head with a toilet tank lid. Good job! Jigsaw's dead, Gordon's family is safe and Adam survived his gunshot wound. Now all that's left is for Adam to get the key to his chains off of Zep's body. But, what's this? A tape recorder? "Hello, Zep." and suddenly the dead guy in the middle of the room starts to rise...
Scarface (1983): The final fight has Tony holding out against the swarm of Mooks invading his mansion, and it seems that he might make it...then he gets riddled with bullets by the Mooks and a shotgun gets fired into his back by the only named assassin of the bunch (the Skull) and he topples over the parapet into the pool underneath, dead.
Sharkey's Machine: Sharkey (Burt Reynolds) is being tortured by a corrupt police officer when he suddenly realises he's still wearing his ankle holster — the bad guys wouldn't be that stupid, would they? Music swells as he slowly inches up his trouser leg...only to find the holster empty. The corrupt cop just smirks and says, "We searched your every orifice."
The Z grade sci-fi action movie Space Marines has a rare villainous example right at the end. The Dragon Gunther yells "it's payback time!"...then the camera zooms out to reveal that he's surrounded by armed space marines. He adds "maybe not right now".
Sunshine: Towards the end, Corazon finds a small plant growing in her burnt-out oxygen garden. They don't have to kill themselves! They can return home and have air! Whoops, got stabbed.
The Terminal: Amelia is able to get Viktor a visa that would allow him to enter New York. Unfortunately, she had to go back to her lover, shredding any chances she had with Viktor. To make manners worse, it needs to be signed by Dixon, who has it out for Viktor after he broke the rules to help the guy with the pills, and threatens to destroy the careers of Viktor's friends if he tries to enter New York. Viktor would have left New York without accomplishing his goal... had Gupta not lent his mop to a plane....
Terminator 2: Judgment Day: Used to very good effect near the end (but only because of the Big Damn Heroes immediately afterwards): Sarah Connor has the T-1000 close to a vat of molten steel, one of the few things that can kill it. Sarah has a fully loaded shotgun and she empties it into the T-1000's torso, knocking it back. As the music reaches its climax... She runs out of shells, and the T-1000 is still clear of the edge of the platform. Its wounds heal, and all hope is lost... Then the T-800 arrives with the grenade launcher.
Thirteen Days: After more than a week of trying to figure out how to deal with the missiles in Cuba, Khrushchev sends a back channel negotiator to probe the possibility of a deal, then sends a message offering to remove the missiles in exchange for a promise not to invade Cuba. The problem seemingly on the verge of being solved, Kennedy sends his staff home, but before the night is out, another message arrives with a much more militant tone and the situation begins spiraling down all over again.
United 93 has a particularly painful example since it's very accurately based on the Real Life September 11 attacks. This applies more for the characters than the audience — anyone watching the film knows how it ends — but when the passengers realize that two men among them actually have flight experience, it really looks like they might have a chance of safely landing the plane.
In the final scene of The Wolfman (2010), we see that Gwen is able to reach Lawrence and stops him from attacking her. It seems, for a moment, that Lawrence may actually pull through. That is, until the hunters show up, and break his moment of clarity, which inevitably forces Gwen to shoot him.
Near the end of Without Warning (1994), the nuclear weapons launched at the second wave of meteors successfully neutralize the threat to Washington, Moscow, and Beijing. And Mission Control Rejoiced. Cue a rather silent Mass "Oh, Crap!" moments later, when a third wave of hundreds of meteors is detected, dooming all life on Earth.
For a second in X-Men: First Class, you're led to believe that Darwin might just survive. Some fans posit that he did.
In X-Men: Days of Future Past, when Magneto and Storm combine their powers to throw the X-Jet into the horde of advancing Sentinels and detonate it to take them out. It looks like it worked... until Storm is impaled by a Sentinel and it's revealed that a large group of them have scaled the cliff from above and below for a surprise attack.