A heavyweight, probably Wladimiar Klitschko, theirs bound to be a few others in that division that can hit harder but just havent been as successful.
If its one punch power, Id rate Shane Mosley right up there. Angulo and Lemieux have hands of stone also.
Gotta be maidana or lemieux, their ko % is amazing! Mosley always been known as the p4p hardest puncher aswell
On the contrary, heavyweights are not considered hard punchers p4p. Sure they punch harder than lower weight fighters but if you divide their power by their weight(that is where p4p comes in), the result is most probably lower than say a welterweight.
The biggest single punch in boxing period is Wladimir Klitschko but P4P Arthur Abraham rings many bells.......................if he can land of them that is
Wlad is one of the strongest HW all time: Foreman Shavers Wlad Lewis Tyson AA still got his power so he must be considered top Donaire, great with Sodorenko, but that wasnt pure power, just nice beatdown