As to why I rented Dallas: first of all, as I have explained before, I think Dallas helped to create the modern TV drama. Previously there was a clear dividing line between soap operas, which were serialized, and dramas, which consisted of completely self-contained stories. By doing -- at least at first -- episodes with relatively self-contained stories that were part of a larger story arc, Dallas helped paved the way for the serialized dramas of the '80s, '90s and '00s.
The other reason I rented it is that it had audio commentaries on two episodes by Patrick Duffy (Bobby) and Linda Gray (Sue Ellen), and I expected their commentaries to be entertaining. I was right, too. For some reason, audio commentaries by actors in late-'70s, early-'80s TV shows often turn out to be delightful; Lynda Carter on Wonder Woman and the stars of The Dukes of Hazzard are other actors whose commentary tracks have charm, humor and good anecdotes. The two actors on these Dallas tracks don't summarize the action or gush about everybody as commentators often do; instead they tell funny stories and are good at poking fun at certain aspects of their show, and at themselves, without ever sounding like they're putting it down. Some good quotes from the Gray-Duffy commentaries:
DUFFY: Remember the actress Ruta Lee? Ruta Lee did a game show with my wife and myself once, and introduced me as "The talking hair from Dallas." Well, I mean, look at it.
GRAY: It doesn't look bad there.
DUFFY: No, but it's a lot of time under the blow dryer. It was before the gel thing. Thank God for gel.
(After a line about J.R. losing $20 million)
DUFFY: Larry [Hagman] once told me that he did the math on this series, and he [J.R.] lost more money than Ewing oil was worth.
DUFFY: On our show, we only had one line in the entire Ewing house, and whoever answered the phone, that's who it was for. It's the most amazing coincidence.
DUFFY: You guys had good clothes.
GRAY: We had great clothes.
DUFFY: And you know, the other shows that tried to copy Dallas went too far over the top -- they got into fashion that was so bizarre; it wasn't classy... are we into the major shoulder-pad era yet?
GRAY: Not quite. Easing into it.
DUFFY: Wouldn't it have been fun to have been on the story meetings? They must have gone through every member of the cast and said "What can he do to him, what can he do to her, what can he do to her." And in one hour...
GRAY: Give everyone a motive.
DUFFY: And they're all acting their hearts out, knowing that if they shot him, they're history on the show.
They also reveal which cast member did the footsteps in the scene where J.R. gets shot. It's not the one I would have expected. And Duffy has a recurring observation about the fact that the show had the ugliest doors on television: they're supposed to be rich, but every door is flat and faded and ugly.
I'm actually starting to think that cheesy shows get more entertaining commentary tracks than genuinely good ones.