I'd have to go with Tszyu, if Tszyu was able to hit Cotto flush once or twice like Urkal did all through out their fight, then it's good night Miguel. I'm not saying this because I like or dislike either fighter, but KT hit like a bastard and Cotto was hurt and dropped by Torres (who admittedly packs a punch), and I think KT, if he hurt Cotto like that, would finish the job.
KT by mid round TKO in my opinion.