While Sia has released a number of albums over the last few years, I think it is somewhat safe to say that most of the U.S. (myself included) was not aware of her until the final episode of Six Feet Under.
I'm not sure the creator(s) of that show could have used a better song than "Breathe Me" for the closing moments of that show. Of course, it was so closely tied to the epilogue that it's hard to separate one from the other. We will never know if anything would have worked as well.
One thing I do love about the song is its simplicity...and its almost demo-like feel.
If you listen to it with earbuds, you can hear the unpolished-ness of the song. But that doesn't make it bad at all. I like hearing the cracks, the audible sounds that anyone else would have cleaned up.
The video version isn't completely representative of the song. The creators put in additional bars of music to extend the montage of the end of the show. The actual song is about two minutes shorter.
....on an almost unrelated note, there is a YouTube version that is another three minutes longer with the intro of Claire saying goodbye to her family on the porch of the funeral home. My friends York and Stuart purchased the front door of Fisher & Sons and it now hangs as their front door of their home.