[DiogenesLamp]

Since you said “comic actor,” the answer is Buster Keaton, with Charles Chaplin a close second.

After movies became talkies, the spoken joke became as important as the acted joke, and comedians shifted accordingly. The top three would be, in no particular order, Groucho Marx, Robin Williams, and Steve Martin.

Excellent analysis, except for Robin Williams and Steve Martin.

Groucho Marx, I agree with, but i'm not sure Robin Williams and Steve Martin deserve spots 2 and 3.

I think Irene Ryan and Bob Denver were funnier.

[dr_lew]

Groucho Marx, I agree with, but i'm not sure Robin Williams and Steve Martin deserve spots 2 and 3.

For sheer genius, gotta go with Harpo. But Groucho and Harpo and Chico together? Fuggedaboutit!

[heights]

Pope Francis?

[chajin]

I think Irene Ryan and Bob Denver were funnier.

OTOH, Irene Ryan only played one role successfully, and Bob Denver two. Keaton, Williams, and Martin were successfully comedic in multiple roles.