Late reply but yes, I can't listen to much ELP, I find Tangerine Dream and Vangelis too much like hard work, but the one standout for me was a band called "Renaissance" loved them back in they day, now just don't get it. The stuff I STILL love is Yes(70s), Genesis (Gabriel era), Hillage, Gong, Soft Machine, Gryphon, Mike Oldfield (TB1 and 2), Floyd, Camel, I could go on
Some modern "prog" rings the bell too. Mostly Autumn, Porcupine Tree, Steven Wilson, King Gizzard and the Lizard Wizard, Psychedelic Porn Crumpets, Khruangbin; I hear a huge prog influence in artists like The Coral, Field Music and Michael Kiwanuka...
I do have to suppress a chuckle when people tell me that punk "killed" this genre. It did no such thing, even at the time sales of the genre "big dogs" was barely affected.