I agree that The Dark Side of the Moon is a reasonable number one, because it's one of those rare records that bring together listeners who usually never talk to each other. It's like Sgt. Pepper: there are albums that were more experimental, more innovative, more accessible and so on, but few or none managed to succeed at all these things at once like The Beatles, or like Pink Floyd a few years later. I mean, I love an album like Selling England by the Pound, but I understand why it's an acquired niche taste.
As for whether it's "prog" or not - well, it's not like "prog rock" has any real definition. I doubt that Steve Harris kept his Jethro Tull and Black Sabbath and Wishbone Ash records in separate boxes the way we do now.
As for whether it's "prog" or not - well, it's not like "prog rock" has any real definition. I doubt that Steve Harris kept his Jethro Tull and Black Sabbath and Wishbone Ash records in separate boxes the way we do now.