Summer Scare Nights: 15 Most Terrifying TV Shows in American Television History

With NBC's new horror series "Fear Itself" debuting, it's a good time to look back at the shows that scared us so much they kept us up at night, from the early days of "The Twilight Zone" to later offerings like "Masters of Horror." While many of the plots may seem cliched today, these shows were terrifying enough in their own time to keep plenty of viewers awake at night.