Everybody can argue, but you have to focus on the strong points of these two fighters! Without them boxing wouldn't be what it is today. Marciano with his toughness and ability to take a punch still inspires fighters today! And Ali with his great ability athletically and charisma. Both were liked but you can't compare the two it is all specualation if you are to say which one is greatest! They were both great champions, there are great qoutes all over the board, just leave what people think about who was the greatest of all time. we all have our own opinions.