Shane Mosley 38 (past prime;prior he had 4 long tough fights )
Juan Manuel Marquez 36 (past prime;fight weight was to high)
Ricky Hatton 29 (good fighter;not a true welterweight)
Oscar De La Hoya 34 (past prime;wasn't great outside lightweight)
Carlos Manuel Baldomir 35 (past prime;decent fighter)
Zab Judah 28 (under-achiever, never beat a very good fighter)
Sharmba Mitchell 35 (journeyman just above average)
Arturo Gatti 33 (warrior but lacked any speed)
Henry Bruseles 24 (nc)
DeMarcus Corley 29 (nc)
The last 8 opponents averaged an age of 33.5 and his last fight he was 33 years old.
Here is a list of ten popular fighter than could have been considered as opponents and he should have fought at least one of them:
Manny Pacquiao (Simple:He wants no part of Manny)
Miguel Cotto (Cotto is mentally tough as they come)
Antonion Margarito (Tall, great stamina and relentless)
Sergio Mora (To much uncertainty)
Paul Williams (Tall, good hand speed and stamina and relentless)
Sergio Martinez (Fast, strong and great stamina)
Winky Wright (Great technician and causes problems for most fighters)
Joshua Clottey (Another physical & mental tough fighter)
Amir Khan (Great fighter and fast)
Andre Berto (Fast hands and combinations)
Vernon Forrest (RIP: Tall and Fast)
Out of all these listed, I feel Floyd should have fought Cotto. Mayweather is bigger, faster, and better all around except for ring confidence. Yes Mayweather has confidence, but Cotto in battle doesn't even consider the word losing or pain and injury. Mayweather is more talk and his fight selection proves it. If he was so confident, he would have taken on one, several or most that I listed. After the Castillo fight he really changed his attitude on TV about fighting the best fighters and put a nice media spin stating he was the best and he had nothing to prove. It reminds me of a poker online scandal just revealed days ago. The accused admitted he was cheating but 5 months prior in an interview he stated he was cheated by close friends so at this point people felt sorry for him and trusted him while all along he was the one cheating his close friends. Back to Mayweather and his poor selection of fighters should show a lack of his confidence in his abilities and shouldn't even be considered. Potential and possessing ability is one thing, going out and performing against the very best is another. Manny does it, Mayweather doesn't! Unlike great fighters who are in a division that at the time lacks talent are in an unfortunate situation, Mayweather had all the choices to make real fights but used his 24/7 promos and side antics to sell tickets on his ability and not the actual competitiveness of the bout. Mayweather did fight a very well conditioned Mosley (38), but Mosley is and always has been a counter-puncher. So when you have a fighter like Margarito attacking you with wid punches it's a perfect fit for you, but having a fast highly skilled defensive fighter that throws and moves, his one dimensional style gets exposed and that is what exactly happened.