Most of the deaths are horrifying (if you don't find their execution narmy), but special mention goes to Jess, who gets a hair straightener burning in her throat. Helped in no way by Laura making it into a hate meme so we get a lingering look at Jess's dead face.
Val's death is the least gruesome, but is no less unsettling. After attempting to call the police, her feed goes out and reappears with what looks like a still image of her in the laundry room, but her cellphone is still ringing and vibrating on-screen. After a moment, a loud banging noise is suddenly heard, and then the camera immediately falls, only showing her feet. The police arrives and rules that she's dead. After hearing the police codes over the radio, Blaire realizes she has a disorder that gives her seizures. The police had cut the feed off before the rest of the cast could find out what's going on. Nothing Is Scarier indeed. There's a bottle of bleach at her elbow. Going by this and scenes in early trailers, the implication could be that she drank bleach.
There's also Ken having his hand shoved into a blender, then cutting his throat with said blender after breaking his hand free. There's something spectacularly creepy about Ken repeatedly slamming his head against his computer while screaming. What did he see, hear, or experience that made him do that?
You can hear him say "FUCK YOU" while this was happening, implying that he was trying to fight Laura's possession and failed.
The entire build-up and reveal that precedes Adam's death. Fed up her twisted game of "Never have I ever", Adam threatens Laura with his gun. In response, Laura sends two printout notes to Adam and then Blaire with their printers, and they're both too terrified to reveal the notes to the others. Mitch, still enraged over Blaire and Adam's affair, demands that Blaire to show them all the picture against her and Adam's protests and threatens to walk out, not caring that Laura will kill him if he does. In a panic, Blaire reveals the letter; "If you reveal this note, Adam will die". Immediately followed by Adam shooting himself in the face with his own gun.
Mitch shoves a knife through his head after Blaire rats him out to Laura. What's terrifying is not only the death, but his girlfriend's willing to rat him out to save her own skin.
Adam calling the police, only to hear what sounds like Laura's eerily monotonous voice.
Laura:Don't hang up Adam: What? Blaire: What just happened? Laura:I said. Don't hang up
Ken finding the camcorder behind the lattice. Given the long, horrified stare he had on his face it can be assumed that he saw something else alongside it, but we don't ever find out.
It's brief, but one of the people Blaire comes across on Chatroulette is sitting in a dark room with his face slightly illuminated. He's watching something offscreen and only his eyes move briefly to look at Blaire when she's calling for help. Brief, but pretty creepy and unsettling.
The ending. After Blaire is revealed to be the one who shot the embarassing Laura Barnes video, she can only stare shocked when her door creaks open. Then, what seems to be Ghost!Laura shuts Blaire's laptop and then presumably kills her.
And this picture reveals◊ that it's actually Blaire's face! Subtle foreshadowing of Blaire's true nature, perhaps? Her grin is certainly more sinister looking compared to Laura's.
That same demonic face is behind Adam to the right when billie227 is making them play the Never Have I Ever game, right after she turns the lights back on in Adam's house.
Near the end where Blaire and Mitch is still forced to play the 'Never Have I Ever', and is being forced to reveal who is responsible for posting Laura's humiliating video online. The stress of the situation eventually breaksBlaire who suddenly yells out of nowhere with a pretty horrific shot of her enraged face, which is made more unsettling due to the poor frame-rate of the video.