Matthew Crawley's Last Ride (Season Three, Christmas Special)
To paraphrase Downton Abbey creator Julian Fellowes' fellow Englishman William Shakespeare, some shows are born to shock, and some have shock thrust upon them. When actor Dan Stevens decided to leave the sumptuous soap following its third season, Fellowes made the most of it, serving up one of the most OMG twists in TV history. In the very last seconds of the very last episode (airing on Christmas Day in the UK, no less!), he killed off Stevens' Matthew Crawely — the show's romantic male lead, heir to the fortune, and hope for the future — in a car accident. Shocking? Senseless? Yes. And such is life.