United States (35 wins, 0 losses, 0 draws, 24KOs)
Unbeaten at super feather and lightweight, Mayweather destroyed Arturo Gatti to win the WBC light welterweight crown. That win combined with Bernard Hopkins' loss puts him at the top of the tree.
Mexico (61-4, 42KOs)
Dispelled any suggestion he was a spent force by beating Morales in the third instalment of their cracking trilogy. Battle-scarred at 31, he remains a force to be reckoned with and a huge draw.
United States (49-3, 25KOs)
Exploded out of the shadows by beating Shane Mosley at light middleweight and put on a southpaw masterclass, stepping up to outbox Felix Trinidad.
United States (25-0, 17KOs)
Taylor claimed the biggest scalp in boxing when he won a split decision over Hopkins and backed that up with a less controversial win in the rematch.
Great Britain (40-0, 30KOs)
The "Hitman" got cut but then cut down WBA champion Carlos Maussa. A mouthwatering showdown with Mayweather could follow in 2006.
Philippines (41-3-2, 33KOs)
Pacquiao was brave in defeat to Erik Morales in 2005. But he gained superb revenge in January, becoming the first man to stop the Mexican.
Mexico (44-2-1, 33KOs)
"Dinamita" clung on to his titles in a controversial draw with Pacquiao and is still in the mix.
United States (24-3, 18KOs)
Victories over Roy Jones Jr and Glen Johnson enhanced his reputation and earned him a place at the top table of boxing.
United States (46-4-1, 32KOs)
"The Executioner" can have no complaints after his second loss to Taylor and he may be only one fight away from hanging them up.
Mexico (53-7-1, 47KOs)
Exacted speedy revenge on Diego Corrales and seems set to move up to the power-packed light welterweight division.