The sight of hundreds upon hundreds of preserved corpses stitched together is unbelievably creepy. Not to mention the way this sight is revealed, and the accompanying music.
"That's not my scarecrow..."
See Eye Scream on the main page. In one version, you can even hear Darry screaming during the establishing shots before the reveal.
The scene where the siblings witness the Creeper throwing the bodies down the pipe. At first he doesn't seem to notice them as he carries on with his business, but then he turns around and just stares at them as they drive past.