Top 20, like around 17-18. That's being very generous though, most people would probably have him at top 30.
It's interesting that people can arbitrarily just throw out a random number ranking, without naming the fighters they feel rank higher. If you don't know all the fighters you'd put above or below him how can you fairly place Pac on an ATG scale. And anyone who says #1 deserves to be called a *******, and this is coming from someone who considers him his own favorite(not best) current fighter.
Had him under top 30 since he beat Cotto and became a legit WW. Hasn't moved much since. Probably won't move much anymore either. And I do believe it's a reasonable number. Having him under top 20 requires serious inspection of whoever is on that person's top 20. Having him outside of top 40 can only mean the person ranking Pac is a ***** and they got Floyd at number 1.
It seems Manny doesn't care how boxing history will see him years from now. If he did, he would have probably taken his profession much more seriously. Plus, his "edge" has been missing since the 2nd Barrera fight. It's okay to be concerned for your opponent's welfare...AFTER THE FIGHT AND NOT WHILE HE IS STILL TRYING TO TAKE YOUR HEAD OFF. If his place in boxing history is not that important enough to him then I guess it would be pretty pointless.