IMO Pavlik; and since Killer and ICB already gave the reasons I won't bore anyone with much more.

Pavlik got shown for what he is, hard as it is to say for me, a fairly one dimensional fighter who had a major case of DITH that night against Hopkins, and was embarassed. Great at what he does and a ferocious finisher; but lacking in mobility and an inherent ability to change a gameplan.

Cotto jut got outbullied by a guy who happens to have iron in his DNA. He showed imo a great ability to box but just got caught one too many times and eventually wore out.

If Pavlik had that same kind of ability to walk through punches like Cotto his fight with Hopkins could have been very similar to the Cotto/Margarito fight. Maybe I'm delusional as I just woke up and my mind is scrambled right now