One of the things I hate is (usually amateur stuff on YouTube) in which the person is getting overly scared even when it makes no sense.
Like they'll over act and start hyperventilating at a leaf and saying shit like "Oh my god what is that?!?!?! WHAT IS THAT?!?!" at like...a thud in the distance.
YouTube and Ghost Hunting shows seem to be the worst offender.
Another trope I hate is a horror game one but it's somewhat related; I hate it when the game tells you when to be scared by having a "sanity" effect or by the player character gasp or scream or whatever. Worst is if they have some kind of heartbeat sound effect that plays when you're supposed to be spooked.
But yeah, if a character starts saying shit like "WhAt ThE FuCk WaS ThAt?!" then I just get more annoyed than scared.
People making obviously horrible decisions or not questioning blatantly strange things
That and it's opposite, very bizarre and strange things happening in front of someone and they are told by people in the know what's happening but they just hand waive it away after seeing a gate to hell open in front of them or something lol