Repeated quotes/phrases and character actions:

Mira a que tiene cosa!!!
Ewwwwww!
Waaaaaahhh!
“Lucy, splain!”
“Oh you poor little thing!”
“Honeybunch.”
“WELL!!!!”
“(Oh) honestly!”
“Hi, girl.”
“Little Riiiiicky!”… “Yes, mommy?”
“Cheapskate/Tightwad”

Fred passing out whenever he has lost (or thought he has lost) a lot of money
Ricky’s eyes popping out of his head in surprise or anger
Lucy's mother calling Ricky 'Mickey' (yet she calls Little Ricky Little Ricky!:crazy: )
Ricky singing Babalu ad nauseum

I'm sure there are many more, so feel free to add!

p.s.: I hope there's not an older post discussing this. If so, I apologize.

How about: "What's the matter with you?-- (are) you crazy or something?"

Yes, right! That one cracks me up and never gets old.

How about: "What's the matter with you?-- (are) you crazy or something?"
I love this line when Lucy is in her tv set and it shorts out, she also added "What are you trying to do, Barbeque me".

How about...You cad!! LOL! I like that one. I use that one on people and the look on their faces are priceless!!

Oh for corn sakes! Ethel, are you gonna eat again? :lol:

How about:

"Oh, come now!"
"You wouldn't dare!" "Oh, wouldn't I?"
"Oh, that's all, brother!"
"Nothin' doin'"
"Yes, sir."
"Well, I hope your satisfied!"

Oh my God, I can't BELIEVE I didn't recall this one (below) -- the MOTHER of all ILL quotes:

"Ricky... Can I be in the show? "No!"

p.s.: Polar, your additions were great!

One Lucy began using in later episodes is "Push tush"

The cliche I hear associated most by casual fans is, "Lucy, I'm home".

"How do you do?"
"Hello, this is Mrs. Ricky Ricardo at 623 East 68th Street."
"Wundaful!"
"Well, thank you very much"

(Ricky yelling): ?Compraste un vestido por 100 dolares? Estas loca o algo? (Not an exact quote, but the general idea, once when Lucy bought a dress for a price they couldn't afford)

The quote may be one-time, but Ricky's rants in Spanish were a trademark; they all sounded the same to me (as a kid I didn't know Spanish). Along with a rapid-fire string of words in Spanish would usually be the words "Lucy" and "loca"