Recently purchased the Jimmy Page autobiography.  There is no question in my mind that Led Zeppelin was a phenomenon that was greater than the sum of its parts.  While all have tried their hand at solo careers, none have stood out the way the band did.  While it seems to me that Plant is being a bit of a prima donna by preventing the group from touring with a new drummer (perhaps Jason Bonham?), there is something that tells me it probably wouldn't do as well as it would be expected.  At any rate, Led Zeppelin has made an indelible mark on the history of rock 'n roll that will never be matched by any other group.  Not to say that there haven't been some very iconic songs and albums by others, but as a legacy, none will beat LZ. (In my less than humble opinion, that is.)