I think that Big Love hasn't gotten the attention it deserves for three reasons: the squeamishness of the general public with the basic premise (a polygamous family), the fact that for whatever reason intimate family dramas are not as "in" anymore, and the weakness of casting Bill Paxton as the Henrickson patriarch Bill. Paxton is the same bland, uninflected actor as he is in all his movies, with his flat, grating voice and expressionless face. A television drama needs a compelling main male character, and Paxton is consistently the weakest actor in the ensemble. After four seasons Bill is still a cipher, and it's hard for a series to gain much popularity that way.
But I watch Big Love instead for the astonishing performances from the rest of the cast, especially the three "sister wives," Barb (Jeanne Trippelhorn), Nikki (Chloe Sevigny), and Margene (Ginnifer Goodwin). The three wives have very different personalities -- Barb is long-suffering and soothing, Nikki hysterical and grating, Margene by turns immature and calculating -- but they are overall a sympathetic, intelligent trio of women. They deserve a better life than bickering over "nights" with Bill and being socially shunned because of their polygamous lifestyle. That's one of the arcs of the show, that women are the core that hold polygamous families together, and the tense but tender relationship between the sister wives is so rare to see on television today -- women who are also true friends. They fight, they have their conflicts, but they also repeatedly present a united front to Bill.
The show also has a wonderfully quirky and well-acted supporting cast. Bill's family still lives on a large polygamous compound, and so does Nikki's family. The characters range from sweet and gentle (Bill's brother Joey) to a tormented, violent closet gay (Nikki's brother Alby). Bill's truly disgusting father Frank and his combative, strange mother Lois are also memorable. What's clear is that in the rigid, strange world of polygamy, there are no winners. No one is happy with the arrangement, everyone acts out in ways either subtle (Lois's keeping her hair short) or outlandish (Alby's desperate attempts to make connections with other males) against such a structured, unjust life. Yet they have a hard time flat out cutting ties because doing so would mean leaving behind family and religious principles that had been instilled in them since childhood.
Big Love is a show with a large cast, but it plays like an intimate family drama. The show takes time to develop characters and relationships, and small details. It is totally in character that Nikki and Margene have shiny new cars, but Barb still drives a beat-up station wagon. There are really no supporting roles; every character is well-developed and part of the ensemble. And although it's natural to recoil at polygamy, the show never judges its characters, and because of that, neither does the audience. The show doesn't have a dogmatic strain to it -- there's dark comedy, drama, even romance, but never a thumping of "These are horrible people!" The finale of the fourth season left the Henrickson family's fate in jeopardy -- Bill had won the election as state senator, but "outted" his family. His relationship with Barb was in tatters, and it was left in the air how much more indignities Barb was willing to tolerate. But Big Love makes us root for its characters, and yes, its families. I know the final season of Big Love will be funny, thought-provoking, dramatic, absurd -- in other words, television at its finest.