What other band from any era has it's own period of time dedicated to it on rock stations? Anyone ever hear of get the Led out? I can't comment on the rest of the world, but in New England, every single rock station has a slot dedicated to play a block of Zeppelin. Particularly the stations out of Boston.
What can be said about Led Zeppelin that hasn't already been said? I guess one of the many things that separate Led Zep from the rest would be musical diversity. They covered everything between fast paced rock like the song that wears it as a title 'Rock & Roll', to acoustic rockabilly songs like Hot Dog. You can't call them a heavy metal band because they were so much more.
It really is a shame that they didn't last just a little longer, having broken up after the death of their drummer John Bonham. They all went to do all their solo gigs... The most successful would seemingly be those of Robert Plant, who came out with hits like 'Tall Cool One' and some others less memorable. And Jimmy Page, who joined up with David Coverdale, then later joined forces once again with Robert to form Plant & Page.
In my opinion, the magic is gone unless the three remaining original members (Plant, Page, & Jones) are together with Jason Bonham on drums. Musically, each knows how to compliment the other in every way, and frankly, just isn't the same when you hear them separately.