''They've been on a planet of their own'' is how title designer Maurice Marable characterizes the Henrickson clan on the Big Love: The Complete First Season DVD set a description that must please HBO, which prides itself on ''redefining'' the TV family. Although Love deals with Utah polygamy, the drama starring Bill Paxton as a man with three wives is surprisingly relatable. By season's end, it's hard not to feel sorry for Bill's first wife, Barb (Jeanne Tripplehorn), who's publicly humiliated and disqualified from the Mother of the Year contest after Roman Grant (Harry Dean Stanton), the sinister patriarch of a scary polygamy sect, makes her discreet domestic arrangement public. Like most of the drama's best scenes, the series concludes its first installment with Barb and fellow wives Nicki (Chloë Sevigny) and Margene (Ginnifer Goodwin) sharing a heartbreaking moment while an anguished Bill looks on his mind atwitter with the realization that his blissful (read: private) existence is about to end. The DVD EXTRAS offer little insight such as what interaction, if any, HBO had with polygamists and the Mormon community. And we wanted the actresses' commentary on the memorable Viagra episode, an hour deserving of their (big) love.