Roy Jones Jr.
Floyd Mayweather Jr.
Oscar Dela Hoya
are better than any of them, but in the past 4 years I would say British fighters might be better than the new American ones, but we'll see... Britain has had some promising amateurs/looked impressive until they fought the big fights(Naseem, Audley who didn't even fight a good competition and still lost), but United States has quite a few (Grant, Lacy, Zab Judah, and a few more who were thought to have the talent, but we found out otherwise). I think british fighters for the most part are better mentally prepared as fighters than Americans.