Animal Crackers"(1930):

Arabella: "Oh, Mr. Ravelli, I want you to do something for me."
Chico: "I do anything for you. What you want I should do?"
Arabella: "You see that painting?"
Chico: "You mean this piksh?"
Arabella: "I want you to take that out of the frame and put this one in its place."
Chico: "You want I should take this one 'a down put this one upstairs."
Arabella: "Yes, that's it."
Chico: "You want I should steal?"
Arabella: "Oh no! It's not stealing."
Chico: "Then I couldn't do it."

Groucho: [singing] "Hello, I must be going. I cannot stay, I came to say, I must be going. I'm glad I came, but just the same, I must be going. La la."

Groucho: "No trains will be sold after the magazine leaves the depot."

Groucho: "I used to know a fellow who looked exactly like you by the name of Emanuel Ravelli. Are you his brother?"
Chico: "I am Emanuel Ravelli."
Groucho: "You're Emanuel Ravelli?"
Chico: "I am Emanuel Ravelli."
Groucho: "Well, no wonder you look like him. But I still insist there is a resemblance."
Chico: "Ha ha ha, he thinks I look alike!"
Groucho: "Well, if you do, it's a tough break for both of you."

Groucho: "Do you mind if I don't smoke?"

Groucho: "My name is Captain Jeffrey T. Spaulding. I bet you don't know what the T stands for."
Chandler: "Thomas?"
Groucho: "Nope, Edgar. But you were close though."

Groucho: "I'll show you a thing or three."

Groucho: "You're the most beautiful woman I've ever seen, which doesn't say much for you."

Groucho: "I came here for a party and what do I get? Nothing. Not even ice cream."

Groucho: "One morning I shot an elephant in my pajamas. How he got in my pajamas, I don't know."

Groucho: "This would be a better world for children if the parents had to eat the spinach."

(While playing bridge)
Mrs. Rittenhouse [about Harpo]: "He has two Aces of Spades??"
Chico: "Yeah, he's got thousands of them!"

"Monkey Business"(1931):

Groucho: [to Chico] "Would you mind getting up off the flypaper and giving the flies a chance?"

Groucho: "Oh, I know it's a penny here and a penny there, but look at me. I worked myself up from nothing to a state of extreme poverty."

Groucho: "...Columbus was sailing along on his vessel..."
Chico: "On his what?"
Groucho: "Not on his what, on his vessel. Don't you know what vessel is?"
Chico: "Sure, I can vessel..." [starts whistling]
Groucho: "Do you suppose I could buy back my introduction to you?"

Man [to Groucho, handing him a note]: "I wish you'd announce this next singer - I can't pronounce the name."
Groucho: [as he tears up the note] "Ladies and Gentlemen! I want to announce that a buffet dinner will be served in the next room in five minutes. In order to get you into that room quickly, Mrs. Shmollahoz will be performaing a soprano solo for us in this room."

Groucho: "Let's look at it this way: the bicycle will never replace the horse. On the other hand, the horse will never replace the bicycle. And that's quite a horse-on-a-bicycle if I ever saw one, and I don't think I ever saw one."

Groucho: "Nice old piece of melodrama, kidnapping a girl. You've been reading too many dime novels!"

Groucho: "You're just wasting your breath, and that's no great loss either."

Groucho: "Oh, why can't we break away from all this, just you and I, and lodge with my fleas in the hills? I mean, flee to my lodge in the hills."

"Duck Soup"(1933):

Man: "Sir, you try my patience!"
Groucho: "I don't mind if I do - you'll have to come over and try mine sometime."

Groucho: "I've got a good mind to join a club and beat you over the head with it."

Prosecutor: "What year were you born?"
Chico: "I don't remember - I was just a little baby."

Groucho: "Gentlemen, Chicolini here may talk like an idiot, and look like an idiot, but don't let that fool you: he really is an idiot. I implore you, send him back to his father and brothers, who are waiting for him with open arms in the penitentiary. I suggest that we give him ten years in Leavenworth, or eleven years in Twelveworth."
Chico: "I'll tell you what I'll do: I'll take five and ten in Woolworth."

Groucho: "Not that I care, but where is your husband?"
Mrs. Teasdale: "Why, he's dead."
Groucho: "I bet he's just using that as an excuse."
Mrs. Teasdale: "I was with him to the very end."
Groucho: "No wonder he passed away."
Mrs. Teasdale: "I held him in my arms and kissed him."
Groucho: "Oh, I see, then it was murder. Will you marry me? Did he leave you any money? Answer the second question first."

Groucho: "Maybe you can suggest something. As a matter of fact, you do suggest something. To me you suggest a baboon."
Ambassador Trentino: "What?!"
Groucho: "I, uh, I'm sorry I said that; it isn't fair to the rest of the baboons."

Chico: "Now I aska you one. What has a trunk, but no key, weighs 2,000 pounds and lives in a circus?"
Prosecutor: "That's irrelevant!"
Chico: "Irrelephant? Hey, that'sa the answer! There's a whole lot of irrelephants in the circus."

Prosecutor: "You haven't been paying your taxes."
Chico: "Taxes. I have an uncle who lives in Taxes."
Prosecutor: "No - Money! Dollars!"
Chico: "Dollahs, Taxes. That's where my uncle is a-from!"

Groucho: "Oh, I'm sick of messages from the front! Don't we ever get a message from the side? --What is it?"
Messenger: "General Smith reports a gas attack. He wants to know what to do."
Groucho: "Tell him to take a teaspoonful of bicarbonate of soda and a half a glass of water."

Groucho: "I'll see my lawyer about this as soon as he graduates from law school!"

Groucho: "Don't look now, but there's one man too many in this room, and I think it's you."

"A day at the races"(1937):

Groucho: "In case you've never done this before, this is known as 'washing your hands'."

Groucho: "How much is this?"
Chico: "That's a-free."
Groucho: "Oh, thank you."
Chico: "There's just a $2 delivery charge."
Groucho: "Delivery charge? But I'm standing right next to you!"
Chico: "Well, for such a short distance, I make it $1."
Groucho: "Couldn't I just move over here and make it 50 cents?"
Chico: "Yes, but I could move back over here and make it a dollar just the same."

Groucho: "Emily, I have a little confession to make: I really am a horse doctor. But marry me, and I'll never look at another horse."

Groucho: "Oh, well, uh, to begin with I took four years at Vassar."
Mrs. Upjohn: "Vassar? But that's a girls' college."
Groucho: "I found that out the third year. I'd have been there yet, but I went out for the swimming team."

Groucho: "She's so in love with me, she doesn't know anything. That's why she's in love with me."

Groucho: "You know, I proposed to your mother once."
Judy: "But that's my father!"
Groucho: "Oh. No wonder he turned me down."

"Room Service"(1938):

Chico: "I still think it's a terrible play, but it makes a wonderful rehearsal."

Chico: "I'm so hungry I see spots before my eyes."
Leo Davis: "Me too."
Chico: "Mine are starting to look like hamburgers."
Groucho: "Well if you see one with onions, save it for me."

Groucho [pointing to Harpo]: "And this is Mr. England, the brains of our organization. That'll give you an idea of the organization."

Chico [about his moose-head]: "I shot it with my own hands; I ate it up to the neck; but I refuse to part with the rest of it!"

Chico: "Hello, Room Service? Bring up enough ice to cool a warm body."