He could take a better punch than he could deliver, and was a ferociously determined fighter who was a pleasure to watch.

Much as I like Mancini, and loved to watch him fight, he is not truly in the top echelon of fighters, nor is he at the top of a "big hitter" list.  He fought hard and he would take three punches to deliver one, but he was no better than above average.

Don't be deceived by the death of Duk Koo Kim in the ring against Mancini.  Kim was overmatched, had dropped a lot of weight to fight Mancini and probably shouldn't have been in the ring at all.  Once it became clear what was going on, the fight should have been stopped, probably in the 10th or 11th.  If it had, Kim would probably have lived, but the fight was allowed to continue into the 14th, and Kim died five days after Mancini dropped him.

Ray was a relentless puncher who was constantly coming forward and would just try to overwhelm his opponent with a constant barage of combos. He needed several punches usually for a KO, didn't really have one punch power.

I honestly believe that Mancini does not belong on this list. If you look at the overall quality of his opponents, you'll see that popularity and his blood and guts attitude aside, he was in all actuality a second string champion. A good decent puncher but not extraordinary. Ironicly, it was Duk Koo Kim's death at the hands of "Boom Boom" that resulted in championship fights being changed from 15 rounds to 12 rounds.