When he to told the world he is the greatest even before he had a title and the usual suspects(the same types that are honouring him today) called him big mouth and arrogant.
On the ring: When he roped a dope Foreman and Knocked him out.
Off the ring: When he gave the U.S. government the finger in it's B.S. Vietnam War. That was epic
When Howard Cosell told Ali "You're being extremely truculent" to confuse him with his superior vocabulary and to establish that he was smarter than Ali and then Ali quickly responded with "Whatever truculent mean, if that's good, I'm that." Boom! Hands down greatest quote of his life! RIP.
To me it was always the first Liston fight. I hold Liston in a much higher regard than Fraizer and Foreman. Liston was a real killer, and Ali was a 22 year old loud mouth who was supposed to get killed.