Walter Matthau - all he had to do is walk into a movie (usually by
          Neil Simon) with that hangdog face and he cracked me up:
   Some samples from the original Odd Couple:

Card player: What kinda sandwiches you got?

Oscar (Walter) : Brown or green

CP: What's in the green?

Oscar :Either very new cheese or very old meat.

(CP : I'll take the brown)


OR


Felix : laughing at Oscar for his ignorance in culinary matters: that's not spaghetti, that's linguini

Oscar : throwing it against the wall: "Now it's garbage"

AND
the look on his face as Felix starts clearing his sinuses in the diner- SPLITS MY SIDES LAUGHING