I contend that Manny Pacquiao is a better boxer than Mayweather.
I will only present simple points to support my claim because I believe that would suffice since my opponent did not bother to post his own arguments.
He is the first and only eight-division world champion. 
He was named "Fighter of the Decade" for the 2000s (decade) by the Boxing Writers Association of America (BWAA), World Boxing Council (WBC) and World Boxing Organization (WBO). He is also a three-time The Ring and BWAA "Fighter of the Year," winning the award in 2006, 2008, and 2009, and the Best Fighter ESPY Award in 2009 and 2011. 
He was long rated as the best pound-for-pound boxer in the world by some sporting news and boxing websites, including ESPN, Sports Illustrated, Sporting Life, Yahoo! Sports, About.com, BoxRec and The Ring from his climb to Lightweight until his losses in 2012.