Which clip has been re-broadcast the most on TV and radio?
I imagine
“We shall fight them on the beaches…”
“That’s one small step for man…”
“A day which will live in infamy…”
The Challenger explosion
are all strong contenders.
“From Dallas, Texas, the flash, apparently official: President Kennedy died at 1 p.m. Central Standard Time. 2 o’clock Eastern Standard Time, some 38 minutes ago.”
“Free at last. Free at last. Thank God Almighty. We’re free at last.”
“We the jury in the above entitled action find the defendant, Orenjal, Orenthal James Simpson, not guilty of the crime of murder…”
Bush reads to the shorties on 9/11.
Bush atop WTC rubble with bull horn
The planes.
The implosions.
Fall of Berlin Wall.
Tank man.
“Oh, the humanity . . .”
My first thought was that astronaut clip that MTV used for years.
Some of the less obvious ones. . .
The Marines hoisting the flag on Iwo Jima (remember when TV stations used to play the Star Spangled Banner every night?)
Los Angeles city hall (the establishing shot for Dragnet and many other shows). Likewise, the Emprie State Building.
Nikita Kruschev pounding his fist at the U.N.
That skier falling down the mountain from ABC’s Wide World of Sports.
Lucy in the candy factory.
Some definite contenders:
Bogart saying “We’'ll always have Paris. Here’s looking at you, kid” to Bergman at the end of “Casablanca.”
The streaker running past David Niven on the 1974 Academy Awards (but always blurred out.)
Welch berating McCarthy (“Have you no sense of decency, sir, at long last? Have you left no sense of decency?”)
Rhett kissing Scarlett as Atlanta burns in the background.
The Beatles on the Ed Sullivan show.
Elvis Presley gyrating on the Milton Berle Show.
Michael Jackson moonwalking.
Antiwar protesters stuffing flowers into gun nozzles in front of the Pentagon.
Martin Luther King making his “I have a dream” speech.
The shower scene from “Psycho.”
They think it’s all over
.
.
.
It is now!
The ships burning in Pearl Harbor on December 7, 1941.
Not nearly as serious, but Joe Theismann’s leg being broken on Monday Night Football is right up there too.
“Today, I consider myself the luckiest man on the face of the Earth.”
“The Agony Of Defeat”
Either that, or something that’s in the public domain and is thus used a lot, like a clip of Hitler giving a speech or something.
“I did not have sexual relations with that woman. Miss Lewinsky.”
“I bet I’ll have you naked by the end of this song” [rip]
Reagan assassination attempt.
“Segregation now. Segregation tomorrow. Segregation forever.”
U.S. Army escort Little Rock Nine to school.
I was on the same street, but I was thinking of the Saturn V liftoff shot, since it’s also been in so many other things as well. Those were on, what, 4 to 6 times an hour, 24 hours a day, for almost 10 years?
What astronaut clip? I’ve never watched MTV.
And, you wouldn’t have seen it if you’ve watched MTV in the past 15-20 years anyway. 
As KneadToKnow mentions, for about the first decade of MTV’s existence, at the top of every hour, they’d run a “station ID” video, which was about a 30-second clip of a Saturn V rocket lifting off, then Apollo astronauts on the moon, with the MTV logo superimposed over the American flag that the astronauts had planted there. While this clip ran (with a rock guitar tune playing), the VJ would mention some of the videos that were coming up.
Depends what you mean by ‘clip’. Here in the UK, the most popular TV show is a soap called Coronation Street that has been running since 1960. For about the first 15 years of its existence, the opening titles remained unchanged, and the show was on twice a week from 1971 onwards. That’s a lot of broadcasts. These opening titles memorably included some film of a cat on a roof. Comedians used to joke about the cat having been stuck on the roof since 1960. But I don’t think this thread is really about opening titles and things that only get shown because they were part of a long-running TV show.
I should think footsge of Roger Bannister being the first to break the 4 minute mile would be a strong contender. Also, all the iconic images from 9/11, Hiroshima and the Kennedy assassination.
The 2nd plane hitting the World Trade Towers.
FDR’s “Day of Infamy” speech.
The little naked Vietnamese girl, running from her burning village.
The girl screaming over her dead friend, at Kent State.
Marilyn Monroe over the subway grate, her dress billowing up.
Kennedy’s car in the Dallas Motorcade.
Johnson being sworn in as President, aboard Airforce 1.
Nixon giving victory sign, entering plane.
“Houston, we have a problem.”
OJ Simpson in white Bronco.
OJ Simpson with glove.
“Mr. Gorbachev, tear down this wall!”