(I'm not even going to bother ranking these because they're all just too good)
Captain Corcoran: One of them goes around with a black moustache.
Groucho: So do I; if I had my choice, I'd go around with a little blonde.
Captain Corcoran: I said, one goes around with a black moustache.
Groucho: Well, you couldn't expect a moustache to go around by itself. Don't you think a moustache ever gets lonely, Captain?
Chico: Hey, sure it gets-a lonely. Hey, when my grandfather's beard gets here, I'd like it to meet your moustache.
Groucho: Well, I'll think it over; I'll talk it over with my moustache. Tell me, has your grandfather's beard got any money?
Chico: Money? Why, he fell hair to a fortune.
Groucho: "Afraid? Me? A man who's licked his weight in wild caterpillars? AFRAID? You bet I'm afraid!"
Madame Swempski: I don't like this innuendo.
Groucho: That's what I always say: love flies out the door when money comes innuendo.
Captain Corcoran: I want you to know that I've been Captain of this ship for 22 years.
Groucho: 22 years, eh? If you were a man, you'd go in business for yourself. I know a fellow started only last year with just a canoe. Now he's got more women than you could shake a stick at, if that's your idea of a good time.
Groucho: I know, heifer cow is better than none, but this is no time for puns.