It's a contentious list (as all such always are), but at number 79: ALFRED HITCHCOCK PRESENTS, whose writers included... Ray Bradbury.

Full list here: http://www.wga.org/content/default.aspx?id=4925

Living writers have been receiving certificates from WGA confirming their contribution to these successful series (Alan Brennert reports receiving one for LA LAW; Harlan Ellison reports receiving one for STAR TREK and one for ALFRED HITCHCOCK PRESENTS).

This list has a lot of great shows on it (many I would pick), but it's bollocks because THE ANDY GRIFFITH SHOW should be at 1, not 70!