Prog is such a wide label it hardly has meaning. Are you looking for modern progressive or classic progressive? Are you looking for something metal-ish or something closer to post-rock?
In any case, here are bunch of bands that someone, once, has labeled progressive that haven't been mentioned yet:
Yes, Porcupine Tree (anything their lead singer, Steven Wilson, touches is gold, honestly. You may also want to check out his amazing solo album), Godspeed you Black Emperor, 65daysofstatic, El Ten Eleven, Tortoise.
In any case, here are bunch of bands that someone, once, has labeled progressive that haven't been mentioned yet:
Yes, Porcupine Tree (anything their lead singer, Steven Wilson, touches is gold, honestly. You may also want to check out his amazing solo album), Godspeed you Black Emperor, 65daysofstatic, El Ten Eleven, Tortoise.