Manny Pacquiao vs Edwin Valero is fun and it'll be a slugfest... but in my opinion Manny will brutalize him inside of four rounds if they ever fight.
Manny i think has underated defense and chin. He's faster than Edwin, has lots of experience fighting elites and perhaps they're equal in power. Manny will have all the advantages.

Juan Manuel Marquez definitely has a better chance of defeating Manny than Marco, Joan, Edwin, Rocky, etc. yet i'll still favor Manny against him. A Marquez rematch is the best and meaningful match for Pacquiao.