If you had to chose today, who would you pick ? For me, not much can change anyway in the next year. For me, It has to be Bernard Hopkins. He fought 7 top 10 pound for pound fighters this decade (Tito, Oscar, Taylor twice, Tarver, Winky, Calzaghe) and didn't lose even one fight clearly (In my opinion he didn't lose at all). He now will fight number 8 , Kelly Pavlik, and don't worry, he will not lose this one clearly too, take my word for it. Did I mention all his fights took place while his age was 36-44 ? Half the decade he was undisputed middleweight champ and he also won the lightheavyweight title, by way of schooling, at the age of 41. Take your pick.
It's like Roy Jones in the 90's. You guys want to reward the guy who ducked his way to the top. If Floyd had the guts (and he doesn't) to fight and beat one of the following three, I'll give it to him: Margarito, Cotto, Williams.
I hate Floyd, but he is undefeated in bigger fights than Calzaghe so that is hard to argue against. My vote still goes to The Executioner.
I am a big Hopkins fan, and if the time period in question was not 2000-2009 but 1997-2005 then I would agree with you, I think he was the best fighter in the world overall between 1997-2005 (because of RJJ's form post-2003), but I don't think he can be said to be THE no.1 2000-2009 because in this period he lost to fighters he would have beaten convincingly in his 1997-2001 prime IMO (Jermain Taylor and Joe Calzaghe). Right now, I would say the best fighter of 2000-2008 (2009 hasn't happened yet) was Floyd Mayweather Jr. HOWEVER, I think Manny Pacquiao can overtake PBF over the next 2 years as the greatest fighter of 2000-2010, depending on what he does in this time period. I have Mayweather slightly above Pacquiao on talent/ability (see N'Dou fight for a true modern masterclass), but Pacquiao ahead on resume (1st win over Barrera, 2nd win over Morales, both fights against JM Marquez - all beat anything on Mayweather's resume IMO other than Corrales). However, with Floyd choosing not to clean out 147 by fighting Margarito and Williams, Pacquiao now has 2 years to achieve enough to pull ahead of Mayweather for this particular award (which is not a p4p award but an award for achievement after all). Pacquiao will lose to De La Hoya but who gives a **** about that fight. IF he can beat JM Marquez in a 3rd fight (and thats a big IF), then unify the lightweight titles against whoever has the other belts then (most likely Campbell, but by that time it could be Guzman or Juan Diaz, slim chance Casamayor) then I would say that Manny Pacquiao has been Fighter of the Decade. But as of now, the answer to your question is Floyd Mayweather Jr.