​Top 10 most memorable ‘Late Show With David Letterman’ moments

After a 33-year run as host of one of late-night television's most popular shows, David Letterman closes his final Late Show on Wednesday night (May 20). With more than 6,000 episodes under his belt, the 68-year-old small-screen legend is the longest-serving TV host in American history, having received countless accolades over the years while interviewing some of the world's most fascinating people – including President Barack Obama, pop star Lady Gaga, fitness guru Richard Simmons and even his own mother on several occasions.

As he prepares for retirement, Dave says he plans to spend more time with his family – wife Regina and their 11-year-old son, Harry.

"For the first time since Harry's been alive, our summer schedule will not be dictated by me. It will be entirely dictated by what my son wants to do," he told the New York Times.

To celebrate the comedian's final show before Stephen Colbert takes the reigns on Sept. 8, Hello! looks back at ten of the most unforgettable moments from The Late Show With David Letterman.

1. In 1982, David Letterman made his debut on NBC. Bill Murray was his first celebrity interview, and the actor would go on to become one of David’s most frequent guests, appearing on his show more than two-dozen times.

2. In 1995, free-spirited Drew Barrymore decided to give Dave the birthday present of a lifetime, flashing the surprised talk-show host while doing a sexy dance on his desk.

3. In 2009, a heavily bearded Joaquin Pheonix made a bizarre appearance on Letterman, acting aloof and giving one-word answers. Later, it was revealed that his strange behaviour was part of an elaborate spoof to promote his mockumentary, I’m Still Here, in which he played a drug-addled actor-turned-rapper.

4. Queen-of-controversy Madonna made an expletive-filled appearance on Letterman in 1994, which was chock full of innuendos and double entendres. The segment was one of the most censored in American talk-show history – they had to bleep the singer a record 14 times – and it also garnered David some of the highest ratings he ever received.

5. After a racist rant made during a comedy routine went viral, Michael Richards – who played Kramer on Seinfeld – appeared on Letterman via satellite to apologize to fans.

6. In 2006, Sasha Baron Cohen appeared in character as Borat to promote his upcoming comedy of the same name. Borat’s antics – including his gleeful discussion of his wife’s death and wacky insights into Kazakhstani culture – sent buzz for the film into overdrive.

7. For his first post 9/11 show, David delivered an emotional monologue that paid tribute to New York, which he dubbed “the greatest city in the world.”

8. David’s late-night mentor, Johnny Carson, made his last TV appearance in 1994 on the Late Show With David Letterman. He delivered the “top 10” list and sat in the host’s desk, where he received a standing ovation before walking off set.

9. To promote her new movie, Striptease, Demi Moore unveiled the “top 10 least popular stripper names” by performing a strip tease herself on stage. The actress came out with the 10 cards attached to her body, which she pulled off one by one, revealing her incredible, bikini-clad figure underneath.

10. In 2002, David Letterman dedicated an entire show to his dear friend Warren Zevon, who had been diagnosed with a rare cancer. The singer discussed his illness at length and performed three songs. He died one year later.

HELLO! Canada magazine is available for your tablet and smartphone. Get HELLO! Canada, PEOPLE, Vanity Fair and over 100 more of the world’s best magazines for one low monthly price at Texture by Next Issue. CLICK HERE to sign up for a free trial.