Hatton is a great fighter even if he is not to be regarded as a p4p fighter. The question put about the two fights between Mosley, Hatton and Mayweather is poor though. Ricky Hatton is not a technical boxer by any means, he always was a high energy, full aggressive, petrol motion, balls to the wall throwback so he went against the wall in that Mayweather fight like he should in an all or nothing display. Shane has a high opinion of himself as a boxer and as puncher so he tried to adjust to and break Mayweather but he was caught by father time rather than by Mayweather as he couldn't sustain the pace, execute and be consistent. See, Shane and Hatton have nothing to do with each other? Shane is the far better boxer and Ricky is a most committed fighter in the sense of taking what he has to take.
I think he did stay in the top 10 p4p for at least a little while after losing to Mayweather because he was fairly competitive. I think it was after his underwhelming performance against retired Juan Lazcano they dropped him.
Other then beating Tzu and Costillo who has Hatton fought worth talking about? (not trying to be sarcastic) He got KO by the two biggest names of his career. Mosley has fought some tough guys and rosed to the occasion with a few of them. Put any of the fighters that hatton fought in front of mosely and he'll beat them (except Mayweather) Since Manny has not fought Mosley, the victor between the two are debatable. Put Hatton infront of Mosely and its lights out for the Hitman.