Definitely the fights that stick out in my mind are:

Mayweather-N'dou (Round 5 was probably one of the best rounds of the decade. When Larry Merchant says that a round in a Floyd Mayweather fight was one of the best rounds of the year, you know that it must have been.)

Mayweather-Judah (I say this fight because it shows Floyd's amazing ability to make adjustments in the face of difficulty)

Mayweather-Jesus Chavez (This fight is what Hatton need stop be studying)