All Those bands are very good. But Pink Floyd just wins it for me. Rush and Queen probably tie as second for me.

Pink Floyd are, great, wonderful, even, but i am of the belief that are NOT the most interesting prog rock band - they were the most recognised for their work in that genre, and they can be given kudos for bringing recognition to prog, and perhaps turning listeners towards other even more complex, interesting bands of the era...

But Pink Floyd made a string of consistently great albums from Meddle to Animals - they rarely missed a beat.

Floyd didn't popularize prog, at least not in it's heyday, they got popular around the time prog was already on it's deathbed. Yes was really the band that got prog into the mainstream.

However Floyd have certainly turned a lot of people towards prog since then.