By Neil Smith
Entertainment reporter, BBC News
The alleged extortion plot involving David Letterman once again sees the veteran US chat show host making headlines.
David Letterman first hit the big time as Johnny Carson's stand-in
It remains to be seen, however, whether the revelations about his private life will have a lasting impact on the popular broadcaster's reputation.
The 62-year-old is so revered that even President Obama took time out to appear on his late-night CBS chat show recently.
His long career has not been without controversy though, as an incident earlier this year involving former vice presidential candidate Sarah Palin showed.
Having made a crude joke about one of her daughters, he was forced to issue an apology for any offence caused.
But then edgy, unconventional humour has been a staple of Letterman's style ever since he first made his name in the 1970s.
A former weatherman, TV announcer and radio talk show host, the Indianapolis native became a celebrity via numerous appearances on NBC's Tonight Show.
The lanky comic proved so popular he became the regular stand-in for Johnny Carson, the late-night show's host since 1962.
In 1982, Letterman took over the post-Carson slot with a late-late-night show that traded off his quirky sense of the absurd.
Typical features included the elevator races he would stage at New York's Radio City Music Hall, "Top Ten" lists of comic observations and the "Stupid Pet Tricks" that quickly became his trademark.
Former Prime Minister Tony Blair is among his many high-profile guests
When Carson announced his retirement in 1992, many saw Letterman as his natural successor as Tonight Show host.
After comedian Jay Leno was given the job, however, Letterman made a high-profile defection to rival network CBS that sent shock-waves across the industry.
Launched in 1993, Letterman's Late Show - aired at the same time as its NBC rival - directly competed with The Tonight Show for guests, audiences and media attention.
For the most part, however, Leno proved the bigger draw, though his successor Conan O'Brien has fared less well in the ratings.
Some suggested Letterman was less irreverent at 2230 than he had been at 2330, for all his pointedly sarcastic, sometimes prickly brand of humour.
Yet that did not stop him incurring the wrath of a Colombian beauty queen in 2001 whom he suggested had a talent for ingesting heroin balloons.
The previous year Letterman underwent an emergency quintuple heart bypass after a test found one of his arteries was seriously constricted.
The surgery led to rumours that he would eventually withdraw from the late-night arena he had performed successfully in for 20 years.
A recent skit saw Letterman share a pizza with pop star Madonna
A decade on, though, Letterman is still going strong, having signed a deal in 2006 that will keep him on CBS until 2010.
A private man off camera, the chat show host has been in a relationship with girlfriend Regina Lasko since 1986.
The couple finally tied the knot earlier this year, having had a son, Harry Joseph, in 2003.
In 2005, a painter working at his home was charged with plotting to kidnap his infant son and his nanny.
The man, Kelly A Frank, briefly escaped from prison in 2007 before being recaptured.
This week's revelations are sure to be embarrassing for a chat show host more used to being the maker of jokes than their target.
The light-hearted manner of his confession, however, suggests his bespectacled face will not be red for long.