Brain Salad Surgery by ELP ( karn evil 9 is the big thing)
literally every King Crimson album
Gentle Knife and Wobbler are some very good recent prog bands
Argus by wishbone ash
Frank Zappa has good prog and some jazz fusion but he has a stuffton of albums. I suggest Hot Rats, Apostrophe', Joe's Garage maybe, Waka/Jawaka and Grand Wazoo.
Pink Floyd is good prog, but if you want proggiest floyd I suggest Meddle and Animals (if you havent already listened to 'em)
Kansas is good prog. I suggest Leftoverture and Two for the Show, because the latter is basically a live "best of" album
uhhjhg i'll think of more Later. At a later time.