Joe Louis in my book.Joe held the Heavyweight Championship longer than any other Champion; Louis scored 43 knockdowns in his first 22 Professional bouts; Only Jack Kranz and Hans Birkie were not floored; He fought as an amateur light-heavyweight (175-lb class); His amateur record reportedly was 50-4 with 43 knockouts
Here is a good video of him(you can turn down the music I did)
[youtube=425,350]lnTDtqiYzww[/youtube]