Interesting to see this article in the Guardian recently by Anne T Donahue, commenting about the recent trend on TV for shocking plot twists, generally involving the deaths of main characters. (Some spoiler here).
Some extremely popular shows are mentioned but there seems to be no doubt that the standard has been set by Game of Thrones, particularly (but not only) with the amazing Red Wedding scene.
“Television’s long, drawn-out narratives used to offer a false sense of comfort against the big beats of two-hour movies. Now, shocking twists are necessary ways of driving the action.”
That’s a comment about TV in 2014 compared with an example from 
a book published in 1996. Well OK it’s about the current and excellent TV adaptation, but that is of course based on George RR Martin’s A Song of Ice and Fire novels. If you have read them you will know that this is just one element of what makes them great, the shock twists are but a part of a much broader realism and complexity.
In all the books I have ever read, the Red Wedding scene has not been surpassed – it would be hard to do so!
CLIVE ANTHONY 