"I knew this day was coming," King said after a montage of highlights played at the top of the show. "It's not easy to say."
He was joined in Los Angeles by frequent guest hosts Bill Maher and Ryan Seacrest.
"This is not a funeral," Maher said. "Larry's going to be in our living rooms, maybe not every night … I would be disappointed in CNN if that wasn't the case. This is the end of a show, not a man."
King, Maher and Seacrest then welcomed a slew of high-profile guests: Governor Arnold Schwarzenegger, who proclaimed Dec. 16 "Larry King Day" in California; Regis Philbin; Donald Trump, Suze Orman, Fred Armisen, who interviewed King as Larry King, from New York; President Obama (via taped message); Barbara Walters (in her 21st appearance on "Larry King Live"); Diane Sawyer (who told King, "We're your protégé, your groupies, your pips"); Brian Williams (who called the show "kind of America's confessional"); Katie Couric (who read a long poem about King); Dr. Phil; Tony Bennett via satellite, who dedicated "The Best is Yet to Come" from a live concert to King; and former president Bill Clinton, in his 28th appearance.
Of course, King's final show wasn't without its awkward live moments, which have become part of Larry King's signature appeal. He thanked Armisen, still in King's character, for allowing "me" to be "inside of you." King also recounted that the first time he met Seacrest, in an airport in Paris, he made the "American Idol" host carry his Louis Vuitton luggage. King later confessed that Seacrest would often buy King jeans, to which Maher proclaimed, "That's gay."
Armisen managed to ask King the question on everyone's mind: "Can the suspender industry survive" without him? King assured viewers that he plans to continue wearing suspenders long after the show ends, thankfully.
Earlier Thursday, Piers Morgan, who will take over King's primetime slot in January, tweeted a "heartfelt congrats … on a fabulous 25-year run as world's [number one] TV interviewer."
But King's best stretch of 2010 came before he announced his CNN retirement, when celebrated his 25th anniversary at CNN with a string of high-profile, back-to-back-to-back-to-back guests — Lady Gaga, Bill Gates, Barack Obama and LeBron James — that helped boost King’s ratings, if only for a week. King also hosted a pair of benefits in 2010 — one for victims of the Haiti earthquake, another for the Gulf oil spill — that did little to help his ratings, but won him plenty of respect.
"Instead of goodbye," King said in his final signoff, "How about, 'so long'?"