"Dallas," the TV show that in many ways created the template for the modern nighttime soap, originally ran from 1978 to 1991. Centered around oil barons the Ewings, the show has had a successful two-season run on TNT, which just renewed it for a third. JR (Larry Hagman) is now dead, both onscreen and off, but Bobby (Patrick Duffy), John Ross Junior (John Henderson) and Christopher (Jesse Metcalfe) will return.