Cosmo Kramer is Jerry's crazy neighbor across the way in his apartment complex.  Krmaer is a ridiculous human being who is constantly known for barging into Jerry's apartment and eating all his food.  Though Kramer never has a steady job, he is constantly scheming throughout the series whether it's making a coffee book about coffee tables or co-creating the Bro with Frank Costanza.

Cosmo Kramer Quotes

Jerry: "Quone"?
Helen: 3031
Jerry: "Quone"? No, I'm afraid that I'm going to have to challenge that.
(Jerry picks up the dictionary.)
Helen: 32
Kramer: No, you don't have to challenge that. That's a word. That's a definite word.
Jerry: I am challenging.
Kramer: Quone. To quone something.
Jerry: Uh-huh.
(Jerry looks up the word.)
Helen: I'm not playing with you anymore.
Morty: Quone's not a word.
Jerry: No good. Sorry. There it is. Get it off.
Helen: (to Kramer) Why did you make me put that down?
Kramer: Nah, we need a medical dictionary! If a patient gets difficult, you quone him.

Kramer (Kessler): You got any meat?
Jerry: Meat? I don't, I don't know, go hunt!

Seinfeld Quotes

I'm disturbed, I'm depressed, I'm inadequate. I've got it all!

George

George: Why don't they have salsa on the table?
Jerry: What do you need salsa for?
George: Salsa is now the number one condiment in America.
Jerry: You know why? Because people like to say "salsa." "Excuse me, do you have any salsa?" We need more salsa." "Where's the salsa? No salsa?"
George: You know, it must be impossible for a Spanish person to order seltzer and not get salsa. "I wanted seltzer, not salsa!"
Jerry: "Don't you know the difference between seltzer and salsa?! You have the seltzer after the salsa!"