<Ed><is><dead>: Recommendations would probably be based on which sub-genre of prog you're interested in. It would be a bad idea to confuse a newcomer to prog with long lists of albums from every genre, so I personally recommend you start with early-mid 70s classic prog. This is basically where prog blossomed after the prototypes that preceded it in the late 60s.
Some of the most popular and accesible albums, which would be ideal for the newcomer, include:
King Crimson- In the Court of the Crimson King (1969)
(Widely considered to be the first 'fully-fledged' progressive rock album)
Van der Graaf Generator - Pawn Hearts (1971)
(Truly epic and unsettling music)
Gentle Giant - Octopus (1972)
(Very clever compositions from a very unique and talented band. Catchy too)
Yes - Close to the Edge (1972)
(Words can't do this justice)
Genesis - Selling England by the Pound (1973)
(Very accesible, and very highly regarded in 70s prog circles)
ELP - Brain Salad Surgery (1973)
(Somewhat more of an acquired taste, but definitely one of the more ambitious prog albums of its time)
As I said, just a starting point (this is where I started). All of these bands produced several more great albums during this period, which are also worth checking out if you like what you hear above. And, of course, don't forget to check out Rush's later 70s albums - 2112 (1976), A Farewell to Kings (1977), and Hemispheres (1978). Rush are probably the best example of a 70s progressive band making a succesful transition into the 1980s (a decade which also yielded some fantastic prog - but that's another story)
