Where do Mayweather and Pacquaio rank....

This is incorrect.

Rios and Algieri are world level fighters who come in on fight night to weigh more than Pacquiao and are wins for a Manny Pacquiao who is PAST PRIME. Algieri will also continue to prove himself at the top level, and I believe he'll establish himself as what would be recognised as a contender level win historically.

In regards to Margarito, he's actually a 'very good' fighter, who had a live chance against the main man Mayweather himself who many neutral fans believe Mayweather ducked. On fight night, there were a huge difference in their sizes, yet Manny utterly dominated him despite being heavily outweighed. It is undoubtedly a huge win and has decent significance historically.

 

3's too low.

 

Perhaps, these list change all the time. Back in the 50's they polled writers who had seem all the older timers fight and Dempsey won by a landslide. That said, the number of defenses he had were pitiful and he took a couple of years off during his reign, so I tend to agree that's too high based on his accomplishments.

 

Whitaker is a clear top 25 boxer ever, to me. Any lower and it'd be like the above Jack Johnson/Sam Langford question I had...

These lists are so up to the beholder. I guess you've got to really widen the "acceptable margin in difference of opinion" because it is so debatable. Everyone values certain things in a fighter differently. Everyone assesses a resume differently...

 

wtf?

 

Both between 50-100 atg. Pac probably ranks a little higher.