I would either assume it's a russian or cuban. I've heard mark breland is the greatest amateur america has ever produced.
Mario Kinderlan? To talk about well known proffesionals, Antonio Tarver, Oscar De La Hoya, Kostya Tszu all had fantastic amatuer careers, Meldrick Taylor was a phenomanon
Have you seen the fight there was like 1-2 points in Jane the whole Cuban team came over we used see them running in there boxing boots was funny actually.
If you could both Olympics and World Championships as titles, then I believe the answer is that both Teofilo Stevenson and Felix Savon won six. Laszlo Papp also won three golds, but that was before the World Championships existed. Rigo won two of each, so it's not him. Breland won one of each, so it's not him. Tarver only won one.
What about Estrada? Or Mike Benntt? heard they were some pretty decorated US AM boxers.... But the cubans are legendary for their boxing accomplishments....I'm sure of the the two cubans holds this title.
They only have championships every other year, which means to have more than six, you'd need to be dominant for over 12 years. No way any American stayed amateur long enough to approach that level. Has to be a Cuban or someone from the Eastern Bloc, since they weren't allowed to go pro. Of active amateurs, I believe Zhou Shiming is the most decorated, with two Olympic golds and two World Championship golds, together with Vasyl Lomachenko (three amateur championships, one Olympic gold). China was supposedly going to let Shiming go pro after the last Olympics, but that never happened. Lomachenko is probably the best pro prospect in the amateurs right now, but he's supposedly going pro after the 2012 Olympics, so he'll never pass Savon and Stevenson.
RIgo is known as one of the greatest Amateurs ever, Odlanier Solis turned down opportunity to go to an Olympics so another Cuban could win his 3rd Olympic medal. Savon has won 3 Olympic medals afaik so id say it's prob a Cuban