Let me add to my list the following:
King Crimson-Starless and Bible Black (heavy)
King Crimson-Larks Tongues (really heavy)
Strawbs-Hero and Heroine (folky elements in this band add character to the prog feel)
Eno-Another Green World (really more "ambient" than prog)
Moodies-Question of Balance
Nektar-Remember the Future
King Crimson-Starless and Bible Black (heavy)
King Crimson-Larks Tongues (really heavy)
Strawbs-Hero and Heroine (folky elements in this band add character to the prog feel)
Eno-Another Green World (really more "ambient" than prog)
Moodies-Question of Balance
Nektar-Remember the Future