The person who runs the show 
- Edit 1
- Edit 1Before modification by Werthead at 26/06/2013 06:52:25 PM
It's the executive producer who has ultimate responsibility for everything on the show.
So, Chris Carter was the showrunner on THE X-FILES, Steven Moffat is the showrunner on DOCTOR WHO and David Benioff and D.B. Weiss are the joint-showrunners of GAME OF THRONES etc.