It's still Mayweather... although technically it's Manny only because he holds that "win" over Marquez that most don't think he deserved. Although ask most fans and they'll tell you that not only did Marquez win that fight, but they'll tell you he's also the better fighter of the two.
I'd still place Pacquiao ahead of Marquez. Knocking out Barrera, Morales, and ODLH is more convincing than knocking out Casamayor, Diaz, and barely beating Barrera.
It's not Mayweather and hasn't been for a long time. Pac and JMM are, in my view, tied for #1. A third fight will sort out thier rankings.
:roll: Only reason Mayweather isn't #1 is because of his so-called retirement. Neither JMM nor Manny has proven they're ahead of him yet.