I came in to mention Bert and Ernie as well.
To some extent, Sonny and Cher.
George and Gracie.
Spock and McCoy, in a way.
John Candy and Steve Martin in “Planes, Trains, and Automobiles”
Danny Devito and Billy Crystal in “Throw Momma From the Train”
Deniro and Charles Grodin in “Midnight Run” though of course Grodin is only playing dumb most of the movie.
Gomer Pyle and Sgt. Carter.
If Bert and Ernie, why not Felix and Oscar? (the Odd Couple)