I couldnt care less about either fighter but Pac has accomplished a lot more in his career than Mayweather.
That's debatable.
Amateur Record
Mayweather
84-6
Pacquiao
60-4
Amateur Accomplishments
Mayweather
3x Golden Gloves Champion 1993 (106 lb) 1994 (114 lb) 1996 (125 lb)
1996 Olympic Bronze medalist (57 kg)
Pacquiao
NONE
_______________________
Professional Record
Mayweather
42-0-0
Pacquiao
54-3-2
Major World Titles
Mayweather (7)
WBC Super Featherweight Champion (130 lbs)
WBC Lightweight Champion (135 lbs)
WBC Light Welterweight Champion (140 lbs)
IBF Welterweight Champion (147 lbs)
WBC Welterweight Champion (147 lbs)
WBC Super Welterweight Champion (154 lbs)
WBC Welterweight Champion (147 lbs)
Pacquiao (6)
WBC Flyweight World Champion (112 lbs)
IBF Junior Featherweight World Champion (122 lbs)
WBC Super Featherweight World Champion (130 lbs)
WBC Lightweight World Champion (135 lbs)
WBO Welterweight World Champion (147 lbs)
WBC Super Welterweight World Champion (154 lbs)
Top Opponents (Consensus)
Mayweather (12-0)
Genaro Hernández (Corner Stoppage Win)
Corrales (TKO Win)
Castillo I (Unanimous Decision Win)
Castillo II (Unanimous Decision Win)
Gatti (Corner Stoppage Win)
Judah (Unanimous Decision Win)
Baldomir (Unanimous Decision Win)
De La Hoya (Split Decision Win)
Hatton (TKO Win)
Márquez (Unanimous Decision Win)
Mosley (Unanimous Decision Win)
Ortiz (KO Win)
Pacquiao (12-1-1)
Sasakul (KO Win)
Barrera I (TKO Win)
Barrera II (Unanimous Decision Win)
Márquez I (Draw)
Márquez II (Split Decision Win)
Márquez III (Majority Decision Win)
Morales I (Unanimous Decision Loss)
Morales II (TKO Win)
Morales III (KO Win)
De La Hoya (TKO Win)
Hatton (KO Win)
Cotto (TKO Win)
Margarito (Unanimous Decision Win)
Mosley (Unanimous Decision Win)
The biggest difference between their careers IMO is, Mayweather has been a consensus Top 5 P4P fighter since 1998 i.e. since at least then he's been in the ongoing discussion of who the best fighter in the world is. Pacquiao, his name wasn't mentioned until at least 2003-2006. So Mayweather has been "on top" in some form or fashion for the majority of his career (after like 2 years as a pro) while Pacquiao just started being mentioned after over 8-11 years as a pro. Mayweather also won his first World Title after only 2 years as a pro while it took Pacquiao almost 4 years. So you can see the difference in how long each guy has been on top.