Tom Skerritt's character crawling around in the ducts gets jumped scared real good.
An American Werewolf in London
First jumpscare was when they were messing around in the moors and then the werewolf attacked. Another jump scare was when the couple were planning on scaring their friends and the wolf attacked them out of the blue.
You could say they're in here, but they're more subtle, tasteful, and necessary than other, more conventional horror movies. No loud sounds which I could remember.
Harry Potter and the Prisoner of Azkaban
When Harry Potter is playing Quidditch, several Dementors appear. The movie uses a POV perspective for some of these moments, and in one of them, all of a sudden a Dementor appears in front of Harry, looking straight at "us" face to face.
At the very last scene, the camera cuts off from the main protagonists walking away in the snow to suddenly a close-up shot of Scrat the squirrel frozen in an ice cube with his mouth wide open and a very scary look. I don't think this was meant to be an intentional jumpscare but for people like me who saw this a a kid, this is absolutely terrifying.
While directing the alien, it slips open in a jump scare. Shortly afterwards, while the president is looking into the lab the scientist's body is slammed against the glass from behind some smoke
This is a horror film with countless jumpscares, including, but not limited to: a skinned corpse is found in the water when a woman is swimming in it. A character that was alive seconds ago suddenly appears with a knife plugged through his neck. A corpse that has its eyeballs hanging from the sockets is found in a darkened room. A walking skeleton breaks through a mirror. A person we think is about to help suddenly stabs a character.
Meet the Spartans
Despite it being played for laugh, the scene where the main protagonist's neck snaps graphically (including part of the spinal column sticking out, accompanied by a loud crunching sound effect) during a dance battle comes out of nowhere and in close up. The character magically survives though. In another scene, a character turns around to reveal he has no eyes (this is, again, played for laughs and looks as fake as can be).
When the first murder occurs, it happens suddenly after a calm scene where the victim is looking out of the window. It is graphic, brutal and loud, filled with intense music and screaming.
A dog suddenly jumps at its owner and kills it.
A character unexpectedly falls into a pit filled with barbed wire. She is later found in another jump scene. In yet another jump scene her dead body that is possessed by an evil force suddenly opens the door with a knife and attacks the protagonist.
This is a rather violent and gory crime thriller about a serial killer. Most of the scenes with the murderer attacking someone (mostly with a knife or an axe) are sudden, but due to the genre and the fact that there are many deaths on screen you can kind of foresee most of them. The most unexpected are an axe breaking through a window chopping off a hand, the killer standing behind the detective as he ducks and a person being suddenly strangled in his car. There are many more though.
The Lazarus Effect
There are multiple jump scares throughout the film, the first one occurs within the first few minutes of the movie, involving a pig.