I rewatched the finale again last night, and, if anything, I cried more the second time around.
On the HBO Six Feet Under Web site they have posted the obituaries of all the main characters.
Webpage Title
This must be the most "final ending" that any series has ever done.
I liked knowing what will happen to these characters in the future, it did add a completeness. And the arc of the last episode, from birth to death, was perfect. There could not have been a more fitting way to end this series.