Top 5 "Classic" Prog albums

[byzantium]

I think it's important not to confuse the notion of 'progressive rock' with the different charactistics of prog which appeal to us as individuals : Why do I like prog? Is it the long, complex songs? The employment of odd time signatures? The experimentalism?

What most prog bands have in common though, is that they challenge the idea most people have about rock in terms of form.