13 years ago, a philosophical thriller created by Dennis Kelly debuted on Channel 4, and it is still as controversial today as it was in 2013.

A television series doesn't need to be universally loved to be considered a masterpiece. In fact, some of the most fascinating shows in TV history challenge comfortable ideas in one way or another. Of course, that can more often than not make them divisive, but a series that invites its audience to question what they watch can be far more rewarding than a conventional thriller that simply tells them what to think.