there are some fights that if they hadn't have happened, boxing would be more interesting today. for example quintana vs williams 1 and williams vs margo. if these 2 fights didnt happen then a potential margo vs williams match up would be totally huge right now.
Hopkins v Pavlik. I reckon this would have made Calzaghe fight Pavlik, or atleast the pressure would have been immense on Calzaghe to take the young pretender on. And slightly of topic, Amir Khan v Prescott should have happened and did. I reckon this does him more good in the long run.
That's a big one. Larry Merchant was heavily implying this during the broadcast just prior to the fight.