The paranoia that permeates the whole story (a reflection of the Real Life time period King was writing about, it turned out).
Ben recounting the childhood incident where he went into the Marsten House on a dare and saw (or imagined seeing) the dead Hubie Marsten hanging from the ceiling and then opening his eyes.
Early in the novel, Larry Crockett hires two men to move a "sideboard" (actually Barlow's coffin) into the cellar of the Marsten House late at night. The two men are immediately filled with a sense of dread and terror that only gets worse as the night goes on. When the two men are in the cellar, one sees a pile of clothing that he assumes is Ralphie Glick's and they haul ass out of the house as soon as possible. When the man tries to express his concerns to Larry Crockett, he not only blows them off, but also blackmails him into staying quiet.
The shortcut the Glick boys foolishly take through the woods to visit Mark Petrie.
Mike Ryerson, burying Danny Glick after the funeral, finding himself increasingly distracted and unable to continue with the job while the sun continues to sink, then suddenly feeling compelled to unlock Danny's coffin and open it, finding the now-vampirized child staring back at him with eyes wide open just as the sun sets completely.
Matt Burke investigating strange sounds upstairs, only to find the now-vampirized Mike Ryerson, who rises up and and commands him to "Look at me!"
Mark and Susan getting captured by Straker while exploring the Marsten House, with Mark getting tied up (in the same room where Hubie Marsten hanged himself) and left for Barlow to "meet" him. Then Mark escaping only to hear Barlow attack Susan in the cellar.
Mark being visited by Danny and later Susan at his bedroom window, after they've turned.
Seeing the ways all the townspeople are slowly turned.
Mr. Flip, Father Callahan's childhood closet boogeyman.
At the end, where Ben is looking at his old snow globe and seeing/imagining himself as a pale, bloodless, nearly brainless vampire, looking up at the real Ben from a window inside the house in the globe.
The 1979 miniseries
The scene where Ralphie is floating outside the window of Danny's room, scratching the glass. In a trance, Danny opens the window, only to have Ralphie bite him.
The prison scene where a man is awakened to a clawed hand opening his cell. When he takes a closer look, we see the sudden appearance of Barlow's face.
