I would say Crass is much better from seeing that they put down the foundation for a majority of punk bands and their ideologies. They also had a much more versatile sound and higher musical ambitions than other bands at the time. I am not understating Discharges sound, but Crass really spearheaded that raw punk sound that was absent from other early punk bands and that Discharge than took off of. Nonetheless, Discharge did D-beat and also high musical ambitions. Obviously, my heart is with Crass, though. Crass was also hugely influential on the squat scene which I believe Discharge was born from. I kind of it see it in the whole Bathory-Darkthrone debate. Who was more influential? Darkthrone may have sold more records, but with Bathory it would have never happened.
Correct me where I am wrong here. Punk is not really my thing.