Genesis, The Lamb Lies Down On Broadway - catchy, bizarre, and just dense enough to make you feel like you've accomplished something when you start to understand the plot. An exemplary rock opera.
Pink Floyd, Meddle - while the Floyd's later albums achieved much more success and acclaim, I still like this one best, mainly for "Echoes," the most amazing thing the band ever did.
Yes, Close To The Edge - If an album can get stereotypical classically-trained-keyboardist Rick Wakeman to cut loose and just rock the hell out, you know it's something special.
The Jimi Hendrix Experience, Electric Ladyland - Absolutely, without question, the man's best work. I've never heard anything quite like his fusion of psychedelic rock and classic blues.
Emerson, Lake & Palmer, Tarkus - It has a giant armadillo tank rolling across an Atari 2600-color plain. If the kickass title track weren't already enough reason to listen to it, the cover art damn well is.
Chicago, Chicago V - While their earlier double-discers are terrific as well, Chicago's first single-disc album enforces just enough restraint to make them really kick some ass.
Chris Squire, Fish Out Of Water - Possibly my favorite solo album by any artist.
Steve Hackett, Voyage Of The Acolyte - Also possibly my favorite solo album by any artist.
Focus, Focus III - If elevator music had some balls, this is what it would sound like.
King Crimson, Larks' Tongues In Aspic - Yes, Virginia, violins can rock the hell out. Intricate arrangements plus kickass proto-grunge equals pure awesome.
Meat Loaf, Bat Out Of Hell - Another one for the "I've never heard anything quite like this" file. Why isn't there more of this operatic rock stuff out there?
The Alan Parsons Project, Eye In The Sky - Alan Parsons and friends managed an extremely impressive feat in making something as esoteric as progressive rock radio-friendly without actually watering it down, and I think this is where they did it best.