Benny teamed with Fred Allen for the best-remembered running gag in classic radio history, in terms of character dialogue.
 Benny alone sustained a classic repertoire of running gags in his own right, though, including his skinflint radio and television persona; regular cast members' and guest stars' reference to his "baby blue" eyes, always sure to elicit a self-satisfied smirk or patently false attempt at modesty from Benny; perpetually giving his age as 39; and ineptitude at violin playing, most frequently demonstrated by futile attempts to perform Rodolphe Kreutzer's Étude No.
2 in C major.
In fact, Benny was a fairly good violinist who achieved the illusion of a bad one, not by deliberately playing poorly, but by striving to play pieces that were too difficult for his skill level.
In one of his show's skits, Benny is a USO performer in the Pacific playing his violin when he comes under fire; Benny still plays his violin when two Japanese surrender to him–all the other enemy soldiers committed suicide rather than endure listening to Benny's terrible music!

A skit heard numerous times on radio, and seen many times on television, had Mel Blanc as a Mexican in a sombrero and serape sitting on a bench.
Jack Benny sits down and begins a conversation.
To each question asked by Benny, Blanc replies Sí.
When Benny asks his name, Blanc replies Sy, which would prompt the exchange, Sy?,
Sí.
And when Benny asks where Blanc is going, Blanc replies, "to see his sister", Sue (Sue?,
Sí.),
who of course sews for a living (Sew?,
Sí.).

A running gag in Benny's private life concerned George Burns.
To Benny's eternal frustration, he could never get Burns to laugh.
Burns, though, could crack Benny up with the least effort.
An example of this occurred at a party when Benny pulled out a match to light a cigar.
Burns announced to all, "Jack Benny will now perform the famous match trick!"
Benny had no idea what Burns was talking about, so he proceeded to light up.
Burns observed, "Oh, a new ending!"
and Benny collapsed in helpless laughter.

Benny even had a sound-based running gag of his own: his famous basement vault alarm, allegedly installed by Spike Jones, ringing off with a shattering cacophony of whistles, sirens, bells, and blasts before ending invariably with the sound of a foghorn.
The alarm rang even when Benny opened his safe with the correct combination.
The vault also featured a guard named Ed (voiced by Joseph Kearns) who had been on post down below, apparently, before the end of the Civil War, the end of the Revolutionary War, the founding of Los Angeles, on Jack's 38th birthday and even the beginning of humanity.
In one appearance, Ed asked Benny, "By the way, Mr. Benny ... what's it like on the outside?"
Benny responded, "... winter is nearly here, and the leaves are falling."
Ed responded, "Hey, that must be exciting," to which Benny replied (in a stunningly risqué joke for the period), "Oh, no—people are wearing clothes now."
In one episode of the Benny radio show, Ed the Guard actually agreed when Benny invited him to take a break and come back to the surface world, only to discover that modern conveniences and transportation, which had not been around the last time he had been to the surface, terrorized and confused him. (
Ed thought a crosstown bus was "a red and yellow dragon".)
Finally, Ed decides to return to his post fathoms below and stay there.
The basement vault gag was also used in the cartoon The Mouse that Jack Built and an episode of The Lucy Show.

A separate sound gag involved a song Benny had written, "When You Say I Beg Your Pardon, Then I'll Come Back to You".
Its inane lyrics and insipid melody guaranteed that it would never be published or recorded, but Benny continued to try to con, extort, or otherwise inveigle some of his musical guests (including The Smothers Brothers and Peter, Paul and Mary) to perform it.
However, none ever made it all the way.

In keeping with his "stingy" schtick, on one of his television specials he remarked that, to his way of looking at things, a "special" is when the price of
Benny teamed with Fred Allen for the best-remembered running gag in classic radio history, in terms of character dialogue.  Benny alone sustained a classic repertoire of running gags in his own right, though, including his skinflint radio and television persona; regular cast members' and guest stars' reference to his "baby blue" eyes, always sure to elicit a self-satisfied smirk or patently false attempt at modesty from Benny; perpetually giving his age as 39; and ineptitude at violin playing, most frequently demonstrated by futile attempts to perform Rodolphe Kreutzer's Étude No. 2 in C major. In fact, Benny was a fairly good violinist who achieved the illusion of a bad one, not by deliberately playing poorly, but by striving to play pieces that were too difficult for his skill level. In one of his show's skits, Benny is a USO performer in the Pacific playing his violin when he comes under fire; Benny still plays his violin when two Japanese surrender to him–all the other enemy soldiers committed suicide rather than endure listening to Benny's terrible music!
A skit heard numerous times on radio, and seen many times on television, had Mel Blanc as a Mexican in a sombrero and serape sitting on a bench. Jack Benny sits down and begins a conversation. To each question asked by Benny, Blanc replies Sí. When Benny asks his name, Blanc replies Sy, which would prompt the exchange, Sy?, Sí. And when Benny asks where Blanc is going, Blanc replies, "to see his sister", Sue (Sue?, Sí.), who of course sews for a living (Sew?, Sí.).
A running gag in Benny's private life concerned George Burns. To Benny's eternal frustration, he could never get Burns to laugh. Burns, though, could crack Benny up with the least effort. An example of this occurred at a party when Benny pulled out a match to light a cigar. Burns announced to all, "Jack Benny will now perform the famous match trick!" Benny had no idea what Burns was talking about, so he proceeded to light up. Burns observed, "Oh, a new ending!" and Benny collapsed in helpless laughter.
Benny even had a sound-based running gag of his own: his famous basement vault alarm, allegedly installed by Spike Jones, ringing off with a shattering cacophony of whistles, sirens, bells, and blasts before ending invariably with the sound of a foghorn. The alarm rang even when Benny opened his safe with the correct combination. The vault also featured a guard named Ed (voiced by Joseph Kearns) who had been on post down below, apparently, before the end of the Civil War, the end of the Revolutionary War, the founding of Los Angeles, on Jack's 38th birthday and even the beginning of humanity. In one appearance, Ed asked Benny, "By the way, Mr. Benny ... what's it like on the outside?" Benny responded, "... winter is nearly here, and the leaves are falling." Ed responded, "Hey, that must be exciting," to which Benny replied (in a stunningly risqué joke for the period), "Oh, no—people are wearing clothes now." In one episode of the Benny radio show, Ed the Guard actually agreed when Benny invited him to take a break and come back to the surface world, only to discover that modern conveniences and transportation, which had not been around the last time he had been to the surface, terrorized and confused him. (Ed thought a crosstown bus was "a red and yellow dragon".) Finally, Ed decides to return to his post fathoms below and stay there. The basement vault gag was also used in the cartoon The Mouse that Jack Built and an episode of The Lucy Show.
A separate sound gag involved a song Benny had written, "When You Say I Beg Your Pardon, Then I'll Come Back to You". Its inane lyrics and insipid melody guaranteed that it would never be published or recorded, but Benny continued to try to con, extort, or otherwise inveigle some of his musical guests (including The Smothers Brothers and Peter, Paul and Mary) to perform it. However, none ever made it all the way.
In keeping with his "stingy" schtick, on one of his television specials he remarked that, to his way of looking at things, a "special" is when the price of 
The Jack Benny Program