It has to be Marquez. Maywaether is a full time celebrity and a part-time boxer. I'd say its better for boxing if Marquez wins. Mayweather is almost using it as a tune-up, IMO its disrespectful to use one of the top P4P fighters as a 'tune-up', it would be great if Marquez shows Mayweather that he is nobodys tune-up. If mayweather wins it will make himself and others believe that he is the only star in boxing - capable of doing as he please as he is so much better than the rest. Personally, id like Marquez to show that NOBODY is good enough to not box for 20 months or so and come straight back and beat one of the best, for me that devalues the other great fighters. The downside would be the loss of mayweather-Pacquaio (if Pac beats Cotto)