The Bigger fight is definately Mayweather-Hatton The better fight will be hard to tell!! You have to bangers in Cotto, and SSM, and you have to prime, undefeated, accomplished Lineal Champions in Mayweather and Hatton who have alot on the line!!
Cotto-Mosely will be the better fight, and probably only of interest to knowledgeable boxing fans. Hatton-Mayweather will be much more heavily promoted and appeal to casual fans (many of my friend who don't know much of anything about boxing are already talking about this one). This one also has the potential to be a real stinker.
Let's put it into perspective. Cotto has his belt because Hatton vacated and Mosley was interim because Mayweather went north. Hatton is the best 140 pounder in the world and Floyd is the best 147 pounder in the world. What sort of question is this.
Mayweather-Hatton will obviously be bigger and greater. Cotto-Mosley could be the better as a fight: more action and entertainment.
I can't believe some people think Cotto/Mosley is bigger. It may be the fight they are looking forward to more, but no way is it bigger and that is as close to a fact as it gets. Hatton has accomplished more so far than Cotto, and mayweather is leagues ahead of Mosley(Mayweather hasn't lost twice to Vernon Forrest!!) Furthermore the total cash generated by Hatton/mayweather will underline my point
Hatton/Mayweather. Cotto/Mosley are big draws but Miguel isn't quite there yet. Mosley isn't as big of a draw as he was a few years ago. Hatton along with his European fanbase is just as big, if not bigger than Mayweather is in the states.