- An episode with Jerry Lewis on the panel featured a guest who was...a bit rotund. Lewis jokingly suggested that the lady made diet pills — which turned out to be her occupation. note
Jerry Lewis: But doesn't she take them at any time?
- Groucho Marx, who for most of Line's run was hosting You Bet Your Life.
- John Daly was noted for, if the panel asked a question that could be answered "yes" or "no" depending on interpretation, first conferring with the guest and then giving a convoluted speech which almost invariably raised more questions than it answered. However, when the famously verbally dextrous actor and singer Danny Kaye appeared as a guest on the 5 November 1961 episode, he turned the tables on Daly by asking a ridiculously convoluted (and deliberately content-free) question:
(the panel have established that self-employed guest Harry Ellswood Jr. makes a product that can be "used up" but is not eaten, drunk, or held in the mouth without being swallowed)note
Danny Kaye: In this product, does the chemical content insofar as the letter of the instance of the product, can you, in turn, with a degree of honesty, feel that there has been, not- not concerning those people who generally don't use it, but would there be - would there be insofar as, knowing a group of people as seated here, could you?
(laughter from audience, panel, Daly, and Ellswood)
Harry Ellswood Jr.: Could you please repeat the question? (more laughter)
Danny Kaye: I'd be happy to. Conference! (puts his arms around Dorothy Kilgallen and Arlene Francis and kisses each of them on the cheek) I don't really want a conference, I want smooches!
- During the Steve Allen era, after the question "Is it bigger than a breadbox?" had become almost standard during the interrogation of guests, the producers used up the last few minutes of one episode by sending out Pete Burg, who made... breadboxes. When Dorothy Kilgallen, having established that Burg dealt with a product that would be found on the ground floor of a two-story home, asked, "But it's not larger than... a breadbox?", the audience fell about laughing. As a breadbox is not technically larger than itself, questioning passed to Steve Allen, who put two and two together.
Steve Allen: I'm gonna take the- the first stab in the dark in a, in a year, is it a breadbox, by any chance? (laughter from audience, panel, and John Daly)
John Daly: (pointing at Steve Allen) What does Mr. Burg do with breadboxes?
Steve Allen: He hides in them!
- After stepping down as a regular, Steve Allen made a number of return appearances as both a guest on the panel and a mystery guest. On the 4 October 1964 episode with Buddy Hackett as a guest panellist, Allen was the episode's mystery guest, but things didn't quite go according to plan thanks to a verbal slip from John Daly:
Dorothy Kilgallen: Are you a performer in show business?
Steve Allen: (loud whisper) Yeeeessss.
John Daly: Mr. Allen- I- (laughter from panel as Daly looks embarrassed) Mr. Cerf.
Bennett Cerf: I'll make believe I didn't hear that.
John Daly: You can't. I'm not kidding...
Bennett Cerf: Are you a comedian?
Steve Allen: (in his normal voice) I'm not as funny as John is right now!
(laughter and applause; Dorothy Kilgallen and Bennett Cerf remove their blindfolds, but Arlene Francis and Buddy Hackett leave theirs on)
Steve Allen: All right, Buddy, three guesses, who is it? (Buddy Hackett starts to remove his blindfold) Your time's up, Buddy!
- When Ed Sullivan appeared as the mystery guest on the 14 September 1958 episode, after trolling the panel by giving wrong answers to several questions, he had the following exchange with John Daly:
Ed Sullivan: (disguised voice) Mr. Dah-ly, why they wear masks?
John Daly: Why they wear masks? So they can't see what's going on.
Ed Sullivan: Then I wear mask too. (produces a caveman-like rubber mask and puts it over his head, derailing Daly's attempt to explain his last answer)note
- The final installment featured John Daly as the mystery guest, swapping positions between host and guest spot and using a high-pitched voice. It was something that was always a planned backup if for some reason they couldn't fill an actual mystery guest, so when this never happened, they decided to use it for the final show.
- Two words: Salvador Dalí. The appearance of one of the 20th century's great surrealists could only herald one of the series' most hilariously surreal rounds, as seemingly every question the panel asked was given a "Yes" answer (as technically, Dalí had been a performer in various media, written books, and been an athlete of some sort).
Arlene Francis: Does he ever do any drawing, like comic strips?
John Daly: Do you ever do any drawing, like comic strips?
Salvador Dalí: Yes. (gales of laughter from the audience)
Arlene Francis: "Yes"?
John Daly: (after pretending to wave goodnight to the audience and leave the stage, he returns to his seat) Our guest says "Yes", he does drawings like comic strips.
Arlene Francis: Is there something quite unusual about our guest? (more laughter)
John Daly: I beg your pardon, Arlene? I missed that last one.
Arlene Francis: I just asked if there was something unusual because every thing he does the audience laughs about. (sure enough, the audience laughs again)
John Daly: No, there's nothing unusual, actually, this sort of thing goes on all the time!
Arlene Francis: Uh... I'm gonna pass to Bennett.
John Daly: Mr. Cerf.
Bennett Cerf: You are a human being? (still more audience laughter)
John Daly: Very much so, Bennett, very much so.
Bennett Cerf: There's no animal or dummy out there with you.
John Daly: That's right, there is no animal or dummy out there with him except, perhaps... (adjusts his bow tie)
Bennett Cerf: (taking the obvious bait) I'm not talking about the master of ceremonies.
John Daly: (standing up in mock outrage) That'll be all, Bennett! That'll be all!
- When Fred Astaire is the guest one of the panelists asks "When you walk down the street do men whistle at you?" This causes Fred to assume the funniest expression, and John Daly has to lean on him, he's trying so hard to contain his laughter. See it here. Fred and John consult on how to answer the question, but both break up at the first attempt to give an answer. They finally calm down, then the audience laughs, so Fred and John lose control again. John finally gives the answer as "no", but he still chuckles as he says it.