Foreman, if you factor in his late 80's and 90's revival is deifinitely a better "boxer" than he is given credit for. Punchers and aggressive fighters who have boxing ability are usually criminally undervalued as mere brutes because most people see things in a linear, or cause-and-effect manner. Foreman elevates himself above these stereotypes.
Still, Ali has four Olymlic gold medalists among his list of scalps (including Foreman's), and he did end up beating the guys that beat him and that Foreman also demolished. Ali also had names from the sixties when they were good in the sixties (Liston, Patterson though he was tapering off, Chuvalo).
Ali's brash, unapologetic civil rights stance, given its time during the socially-charged 1960's, will always be conflated with his boxing greatness, and this unduly inflates his boxing legacy. Let it be known that I believe Ali to be the better boxer because of his consistency over time, willingness to figt anyone (Foreman picked a bit in the 90's), and his skill in rematches (3 of 5 losses avenged), his number of quality names on his resume. As a sidebar, yes, I consider fighters like Ken Norton as an A level boxer - in many other eras he would have been a clear champ, and if he won that split against Holmes we suddenly look at him and Holmes very differently. It is funny how much power rests in one man or woman's scorecard, no? Or, even Ali's split wins against Norton.
I like this thread because it made me reevaluate, but I still land on the same answer.