the porter/thurman fight had huge viewer ratings i heard. the win, even so it was a bit close, was a huge win for thurman against a top shaped prime ww. thurman is prime. even so pacquiao would be the favourite, cause pac also looked great in his last bout, yet still thurman would pose some problems, he would be the bigger stronger, harder puncher guy in the ring and prime, with pac past prime, still dangerous. i think ppv also a lot of people would get interrested, cause you sure as hell wouldnt get a boring fight.
if we talk, straight up quality, than it has to be pacquiao-spence. an atg against a future p4p king (or p4p prince #2, since lomachenko is around