They are three good choices b there have been a lot of guys with heart out there...a few who were not champions but had hearts that could not be measured....

Frazier,Holyfield,Marciano,Dempsey,Tony Galento,Chuck Wepner, Tex Cobb, Jerry Quarry, George Chuvalo, all huge hearts...not all the most talented fighters skill wise but heart wise it is all a close race