I'll skip the obvious pun about the death of a show about death and just say that I found the final episode of Six Feet Under to be as deeply moving as a real funeral.
As a het dude, 6FU hasn't been my favorite HBO show (it's probably fifth behind, in order, The Wire, The Sopranos, Deadwood, and Inside the NFL, which I've been watching since it starred guys who played in single-digit Super Bowls). But it's always been a powerful show, and I've admired the unflinching and nonjudgmental darkness of it all, as well as the complexity and realness of the characters.
Steven Johnson, who wrote the engaging if not entirely convincing Everything Bad is Good for You (see the book link on the left), really hits on what made 6FU truly unique in the conventional world of television: the aftermath of death, the ugliness and ordinariness of Los Angeles, the meaning of grunge, and the matter-of-fact ubiquity of drugs.
I think the Grunge factor really helped me connect with the show. From Johnson's post:
I've always felt that Six Feet was one of the very few popular narratives that internalized whatever cultural shift happened with Nirvana in the early nineties. Both Nate and Claire always seemed like distinctly post-Kurt-Cobain characters to me -- outsiders intrigued by drugs and contemptuous of mainstream society who were at the same time resolutely NOT hippies.
Indeed. "Grunge" at this point is sadly forgotten as little more than a musical fad in flannel, but for white, educated Gen Xers (among whom Nate would have been on the leading edge), Grunge was an important stage in the development of the American psyche, a cynical and disillusioned hangover following the Reagan '80s. Given our usual 20-year nostalgia cycle, we can expect a Grunge revival in five years, but it won't capture the meaning of the era the way that 6FU did.
Oh, and as for the finale: It was the first television show to make me cry ever. Here's the spoiler: it ends the way every story really ends after it "ends." Everybody dies.