With or without Frazier, Ali should be No. 1 amongst heavyweights. It's all about his skill, his genius and his character, and it's not about his opponents BUT HOW HE FOUGHT THEM.

Ali would still be at the top. True the Frazier fights defined his greatness. However he still beat 2 unbeatables Sonny Liston and George Foreman. He was one of a kind. There will never be another Ali.

Take out Frazier and he still beat Foreman, Liston, Patterson and Norton.

Still no. 1

I mainly consider him the greatest heavyweight fighter of all time because of the incredible skills he had in his prime (1964/65/66/67).