Was Six Feet Under a popular series in the US?

Several weeks ago I began watching Six Feet Under on DVD, I’ve just finished Series 4 and impatiently waiting for Series 5 to become available from the library. I don’t think I’ve enjoyed a programme so much, it is stupendously good, the humour is wonderful, the characters are gorgeous, it is outstanding rave rave rave rave . After the first episode I thought oh yeah, could be good, I’ll watch another episode, by the second episode I was hooked. I had never before seen an American programme that utilised irony, I decided Americans don’t get irony… I was wrong.
* because I haven’t yet watched Series 5, please don’t, please please don’t give anything away…