Was it even a question? Ali is the greatest because he backed up everything he said and was the most creative. He had rhymes for days and always had a clever comeback. From an early age, Ali had the gift of gab. He psyched out Sonny Liston at the tender age of 22 and managed to get Joe Frazier so mad at him, the two continue to beef 'til this very day. He beat people to a pulp because they kept calling him Clay and told the world when he was going to knock fighters out. Ali is the greatest boxer and the greatest trash-talker of all time. Watch the clip above to see the legend in his element.