I like to think of being the best p4p as purely that, rather than what a fighter's resume looks like, or who's is easier to pick apart or slant yada yada. For me I think Jm Marquez and Cotto, along with Pac, are all BETTER fighters than Calzaghe. My top five was

1.Mayweather
2/3.Marquez/Pacquiao, rank them either way so little to seperate them..
4.Cotto.
5.Calzaghe
6. Joan Guzman( I read someone who posted he could be their number 2 if it were based purely on talent, I'm tempted to agree the more I watch him).

P4p lists are always a pain in the ass for me, because I like to chalk it up as the best fighters, aside from who has the greater resume, wheras most seem to favour the opposite way of thinking. Now obviously you aren't going to find fighters who arent that good yet beat great fighters, however simply because a certain fighter doesnt have multiple greats in his W column, doesn't mean they dont have more ability than some who do.