Ceiling fans in dark rooms. I had a fan in my room that had exposed screws, so light would glisten off of them and make them look like eyes. It always "stared" at me whenever I was in bed as night, but if it was daytime I was fine. I even remember a nightmare where the fan unhooked itself from the ceiling, flew towards me, and cut my throat open with it's blades. Dream blood went everywhere.
I was also afraid of pterodactyls flying through my windows and carrying me away at night, but the fan fear was worse.