This is never more apparent than in the character of David Fisher, played by the brilliant Michael C. Hall, who has had the most post-SFU success as the titular Dexter on Showtime (which is quickly becoming the destination for quality TV as HBO's franchises retire in succession). At first glance, the two characters seem very different, but they actually have a great deal in common.
*Spoilers to both series follow.*
David begins the series as a closeted gay man, battling his own homophobia and self-loathing. He is totally repressed and conservative, from his bottom-down attire, to his cold, controlling interactions with family and clients. Even as he comes out, he is hardly ever at ease with his life, struggling with how his sexuality defines him. He insists on living with what society has deemed as normal.
Dexter hides his life as a vigilante serial killer, and turns his loathing outward, to a world and to people he does not understand. He represses and channels his urges using the "Code of Harry," killing only those that have wronged society yet fallen from justice's blind grip with a cold, clean, bloodless brutality. Dexter is forever grasping for normality, figuring out what society expects, and faking the appropriate reactions.
They both love broken people. Dexter purposely seeks out the battered Rita; abuse has left her just as asexual as Dexter, and she becomes his 'beard.' And as Rita heals, Dexter begins to legitimately feel affection for Rita and the kids, a strange tinge of compassion that had previously been limited to his sister. Keith is David's soulmate, but he must deal with the scars of an abusive father and reconcile his sexuality both with his race and his hypermasculine professions. These couples may be damaged, but they're damaged in all the same places.
The fathers of David and Dexter loom over them, even in death. As he works to maintain the family business and follow in his father's footsteps, David is haunted by his father's disapproval (although since they only interact in dreams, we only get one side of the story, as David projects his inward anger onto his father's ghost). Dexter's father saves him from the tragedy that created him, and crafts a set of rules that will allow him to live in society. However, as Dexter is still a story in progress, we'll have to see how he lives now that the truths about Harry has allowed him to stop deifying his adoptive father.
The characters also have significant relationships with their older brothers (who both die young, Brian at Dexter's hand and Nate by David's side). Both sets of brothers are two sides of the same coins. Dexter and Brian are both irreparably corrupted after witnessing their mother's brutal murder, Scarface-style. However, as Dexter is molded by Harry, Brian's demons are allowed to fester into the Ice Truck Killer. And while Nate tries to run from the funeral home that dominates their family, David tries his best to make peace with Fisher & Sons.
One of the central themes of Six Feet Under is finding purpose in life. After struggling for his entire life, David finally finds happiness with Keith and their adopted sons, continuing the tradition of Fisher & Sons, and eventually pursuing his musical interests in retirement. As he dies, he sees Keith one last time, and his final expression suggests that he's ready to die, even if there is nothing beyond. Once again, Dexter's entire story has not been told, but the end of the second season definitely entails a turning point in how Dexter will continue to define himself.
Michael C. Hall deserves a lot of credit for making these characters refreshing and real, but a lot must go to the writers and casting directors who saw his potential for such tormented characters, both in Six Feet Under (2001-2005) and Dexter (2006- ).
