When he was in his prime - before he was forced out of the ring by politics - Ali was in a class by himself as a boxer. As a person, he had strengths and faults, like any human being would. I think the one thing that impressed me most was something that happened after his first fight with Joe Frazier. Bundini Brown, his assistant trainer, wanted him to leave Madison Square Garden without talking to the press. Ali refused, saying that he talked to the press when he won, and would talk to them when he lost. Perhaps that's a minor occurrence in his career, but it said something to me about the man.
I saw him once in person during his forced banishment from the ring when I was in college. And somewhere, I have a copy of the LP he recorded for Columbia around the time when he first defeated Sonny Liston.
He left me with a lot of memories of all kinds. Rest in peace, sir.