Do you want to cover everything? stand up and comedy acting in movies & TV?
There's a lot of choices from the people that came up through Vaudeville & Burlesque, then into TV as it evolved:
Harold Lloyd
Buster Keaton
Marx Brothers, Groucho in particular
Three Stooges
Ritz Brothers
Milton Berle
Jackie Gleason
Lucy Ball
Phil Silvers
Sid Caesar
Jonathan Winters
Ernie Kovacs
Steve Allen
Jimmy Durante
Danny Kaye
Bob Hope
Carol Burnett
Johnny Carson
Shecky Greene
Danny Thomas
Jerry Lewis
Dean Martin
and later
Smothers Brothers
Flip Wilson
Richard Pryor
George Carlin
If you just want stand up in the last 20 years I'd say Gallagher.