@ Crowquill and all I suppose
I only dismiss your Britney Spears and Joy Division point because it is not relevant to the discussion. I am referencing the Greatest selling Artists of all-time Michael Jackson, Elvis Presley, The Beatles and Frank Sinatra are 1 through 4. Collectively they are: The King of Rock, The King of Pop, The Chairman of the Board and "Bigger then Jesus". #5 is Led Zeppelin. See my point. The Cliche, trite as it may be, "You are judged by the company you keep" rings ever so true. Do you see my point? You might "accidentally", to put it plainly, have commercial success as Britney Spears did for a few years in the early part of the decade, or as Johan Pachabel did with Canon in D. But in the end the Mozart's and Beethoven's will have inevitably surpassed you much like the Beatles, Old Blue Eyes and Led Zeppelin have.
In regarRAB to your correct point that a two album head start is hardly paving the way for an band that undoubtedly had an established sound: I'm not crediting Zeppelin with influencing Sabbath, only with bringing a style of music to the mainstream that allowed for an easier path to in crowd super stardom for Ozzy and the like. Similar to Nirvana's impact on the 90's Music scene and the subsequent popularity of previously fringe genre banRAB like Soundgarden and Pearl Jam etc.
I like your list, I like my list, my only point is that all lists are inspired by previously lists and the flaws we personally assess to them. My list is far from original but it's individuality can not be challenged and as I have mentioned so many times before, it is still be molded by trial and error. If you want recommendations of Zeppelin songs to listen to I'd be happy to oblige, in fact if you like I'll purchase their entire catalog via Itunes if it would be suitable for you. My list started with several off the beaten paths selections that were beaten down by popular opinion. Both here and in other forums, there is a reason most professional done lists look similar, Because they are well researched and accurate. When I wrote about Rock Music, I'd hear myriaRAB of opinions on greatness and influence but the same ones that some people here have charged as tacky or redundant are the ones that I'd hear most frequent and passionately. So I hope, regardless of your independent thoughts, where I am coming from with mine.