I actually consider Physical Graffiti to be one of the greatest albums ever made by anyone, it's virtually flawless, the only track I would question is 'Boogie With Stu', which I usually skip that track when I'm playing the album, and in which to me they sound like a pub band performing a sound-check, but not even a good pub band! - but 'Graffiti' still gets my vote, ahead of IV and III....though LZ were incapable of producing anything less than genius right up to 'In Through The Out Door', which for me has only one track I even ever listen to, the epic 'Carouselambra' - though I read that Bonham was permanently drunk, and Page was strung out on heroin addiction for the duration of that whole record, so that would maybe explain it.