Television as an artform has certainly gone through its ups and downs. While I generally have an idealized vision of my youth, that certainly doesn't include the quality of the TV shows during the 70's. They don't hold a candle to what's available now. Why?
First, I think we owe a huge debt of gratitude to a trio of gentlemen: Stephen J. Cannell, David Lynch, and Chris Carter, and to a lesser extent Dick Wolf. Stephen J. Cannell developed and produced of The Rockford Files and The A-Team, but it was his visionary work on Wiseguy that really took television in a new direction. This series, which starred Ken Wahl as a cop very deeply under cover with the mafia, ala Donnie Brasco, refined the concept of season arcs. Though arcs within television shows were not unheard of, Wiseguy featured complete arcs over an entire season. A new set of villains would be featured in the second season, and yet a third set in season 3. The story arcs within these seasons were resolved. Within each episode there is also a central challenge for Vinnie to overcome. It meant action packed television that rewarded viewers who watched the entire season.
At this point, it is necessary to mention that the rise of videocassette recorders made this kind of television possible. A person could record the episode to watch at their convenience--they didn't have to worry about missing an eposide and falling behind on the story arc. In this way, VHS technology improved the quality of television.
Taking the next step, David Lynch in Twin Peaks offered a story arc that was really a pretext for showing the lives of a large cast of small town characters. Its odd, quirky mix of humor and darkness created a legion of fans. More than any other TV show, Twin Peaks brought cinematic lighting, editing and acting to the small screen. The visuals were complex and carefully constructed. Compare any episode of Twin Peaks with Charlies Angels, The Bionic Man or Happy Days. The washed-out studio lighting of the latter is flat and inert. On the other hand, Twin Peaks offered a wide range of color, from super saturated reds to almost black. The richness of the visuals hinted at something powerful and ominous under the surface--which is a quality in all of David Lynch's film workas well.
Finally, Chris Carter took the groundwork laid by Cannell and Lynch and combined it in the X-Files. Not only the filming techniques, but also the storytelling concepts. Carter's first season featured stand alone episodes, but with each one, certain elements began to stick--who was that mysterious smoking man that never said anything? What mysterious, powerful invisible forces stood in the way of Mulder's search for the "truth?"
The cinematic quality of the X-Files is also plainly evident. Perhaps it was simply the TV studios had finally recovered from their love-affair with color television, that they permitted a darker chiaroscuro. In some ways, X-Files feels more like a black and white show than a color show--it has the same sensibility of light and shadow.
These three series form the transition from 70's cheesecake to 80's grit to 90's noir. There were others to be sure: The Streets of San Francisco; Law & Order; Miami Vice; NYPD Blues all come to mind. But for sheer innovation, Wiseguy, Twin Peaks and The X-Files are peerless.
They have ushered in the 21st Century and made The Sopranos possible--which in itself is the culmination of the novel for television concept, a work of series storytelling genius.