10. Because every episode is suspenseful and creepy.
At first glance, the series can be confused with a PSA about cyber bullying. But when one of the girls actually dies (with more being buried with her) and the others are getting death threats via text messages, you realize the show isn’t exactly an afternoon special.
Between the tech-savvy sociopaths, the eerily prophetic children, the eyeless dolls and the creepy old ladies, Pretty Little Liars is essentially a series of campfire stories with an elusive murder mystery as the core narrative thread.