Man, you skipped over a lot of classic Progressive rock in that post... I mean, I'm not much of a fan, but I would think that no Progressive rock thread could even be started without Emerson, Lake & Palmer. The only Prog-rock band I really like, as all the others are too soft for me; but I would still suggest some Yes and King Crimson, as well.
I also gotta give a nod to Prog-rock's little brother, Space Rock, specifically Hawkwind: Master of the Universe, Brainstorm and Upside Down. More standard rock, but I still love it.
Bookmarks