Game of Thrones is nothing if not about backstabbing and betrayal while each character tries to ascend the Iron Throne. I'm impatiently waiting for next week's debut of Season 7, and in the meantime I've been reading up on all things Thrones. I came across an infographic that venngage made to show every betrayal that ever happened on the show.
Beware there are spoilers (obviously) for Seasons 1-6 if you haven't caught up yet (why haven't you?)
The graph shows that "to deceive is, usually, to come out on top. The characters who by the end of the sixth season have the most power have also committed the most acts of betrayal. Most of their victims are dead and their houses decimated. "
I have to admit, there was a surprise on the list for me. I think clearly Cersei and Baelish stuck out as being the most devious on the show, but I wouldn't have guessed the guy in the middle of the graph. Now that I see it, it totally makes sense though!
Find the graphic here: https://venngage.com/blog/game-of-thrones-infographic/
Find an analysis here: http://www.thewrap.com/game-of-thrones-betrayals-data/