Access Top 10: 'The Oprah Winfrey Show's' Best Celebrity Moments

Access Hollywood - May 23, 2011 3:12 PM PDT

By Erin O'Sullivan

LOS ANGELES, Calif. -- She's groundbreaking, thought provoking, and an incredible inspiration to millions of people around the world, but after 25 years as the host of "The Oprah Winfrey Show," the queen of daytime talk television is calling it a day.

For 25 years, Oprah Winfrey has been the trusted go-to gal for the biggest names in Hollywood with a story to tell, and she's also been committed to delivering crucial health news and uplifting, tear-jerking stories, all the while providing a constant reminder to strive to overcome adversity.

"The Oprah Winfrey Show" has seen countless noteworthy star moments during its quarter-century run - from Kirstie Alley's weight loss celebration to Tom Cruise's enthusiastic couch-jumping.

Additionally, Oprah's daytime dominator became a safe-haven for celebrities such as Tyler Perry and Mackenzie Phillips who had (sometimes excruciating) secrets they were finally ready to reveal, as the beloved host had proven time and again she could be trusted to treat their stories with respect and dignity.

As Oprah heads into the final episode of her talk show, set to air on Wednesday, May 25, AccessHollywood.com is taking a look back the Top 10 Celebrity Moments of "The Oprah Winfrey Show."

#10 - A Whole Lotta Osmonds! (2007)

Just how many Osmond family members can fit on Oprah's stage? 126! That's how many Osmonds made the trek to Harpo Studios in Chicago, for an onstage family reunion in 2007.

Sadly, what was supposed to be an upbeat gathering of one of the nation's most beloved show business families quickly evolved into a celebration of the life of Osmond family patriarch (Donny and Marie's father) George, who passed away at the age of 90, just two days prior to the taping.

Show producer Tara Montgomery, who was assigned the task of orchestrating the episode, waited anxiously for the cancellation call, but instead received a call from Donny announcing that the family had delayed George's memorial service in order to appear on the show because they were committed to coming together and celebrating their family.

"I've worked here 16 years," Tara said in an article posted on "The Oprah Winfrey Show's website. "I've worked with every celebrity that you can think of, and there is no doubt in my mind, if anybody asks me in 30 years, 'Who was the nicest celebrity?' [It's] Donny Osmond and his family."

#9 - Tyler Perry's Abusive Childhood Revelation (2010)

A long time friend of Oprah's, "Madea" star Tyler Perry made numerous appearances on "The Oprah Winfrey Show" over the years, but it was his visit in October 2010 that took on a shockingly different tone.

During the incredibly emotional sit-down interview, Tyler revealed painful childhood secrets that he had previously chosen to keep private for the sake of his mother.

"[My mother] suffered so much horror in her life -- surviving breast cancer, the abuse from my father, the belittling, the beatings. And I just could not be a source of pain," he told Oprah, of his previous decision to keep the dark secrets of his past quiet. "I knew if I spoke about this, that she would be hurt. So I didn't."

But it was his mother's death - in 2009 - that freed up the movie mogul to finally share his truth with Oprah.

"I feel this tremendous sense of, 'Now it's time for me to take care of me and get some of this stuff out of me and be free from it,'" he said on the show.

The actor/producer/writer/director proceeded to reveal his hidden past - ripe with alleged severe sexual abuse by four different adults (male and female), a suicide attempt and claims of violent beatings at the hand of his father.

"To this day, I don't know why he did it, but I remember him cornering me in a room and hitting me with this vacuum cleaner cord. He would just not stop," Tyler told Oprah, of the abuse he allegedly suffered at the hands of his father.

"My mother was truly my saving grace, because she would take me to church with her," he later revealed. "I would see my mother smiling in the choir, and I wanted to know this God that made her so happy. If I had not had that faith in my life, I don't know where I would be right now."

#8 - Black Eyed Peas Flash Mob Surprise (2009)

When Oprah kicked off her 24th season, the Black Eyed Peas were there to get the party started -- along with 20,000 fans!

The massive Chicago crowd performed a choreographed dance to the Peas' catchy feel-good anthem, "I Gotta Feeling," to the shock and amazement of Ms. Winfrey, who stood on stage -- mouth agape -- capturing the fun with her flipcam.

#7 - John F. Kennedy, Jr. (1996)

Three years before his death in a tragic plane crash in 1999, Oprah sat down with JFK Jr. for a highly coveted interview with the handsome then-bachelor, and the chiseled publishing chief opened up about life in the spotlight.

"[Caroline and I] are used to a certain degree of being watched," he told Oprah. "I understand that there's interest, and certainly that interest has given both of us great opportunities, so I can't complain too much. Sometimes I wish it wasn't always that way, but then you wouldn't have invited me on your show if I was just somebody else."

#6 - Sidney Poitier's Surprise Appearance Brings Oprah To Tears (2005)

"Never in the history of doing the show have I had a breakdown afterwards - that is, until my interview with Sidney Poitier was over," Oprah said of her 2000 interview with the legendary actor - the first ever black actor to win an Oscar -- during her 20th anniversary special in 2005.

"I had watched Sidney Poitier win the Academy Award as a 10-year-old girl and I thought, 'If he could do that, I wonder what I could do?' So he was, and has been, and is an enormous role model for me... After that interview I went into the control room and I sobbed and cried because I felt I was not good enough for Sidney," she said.

How Oprah could feel "not good enough" is a mystery of its own, but she proceeded to explain in the anniversary special that she felt she didn't ask the questions she should have during the sit-down. Oprah also admitted to feeling frumpy in the dress she was wearing at the time, and "hated" herself for what she felt was a failure in front of one of her heroes.

"I felt like [Sidney] would never know that I was a smart person with a brain in my head because I didn't remember what I said," she explained.

To the delight of the studio audience -- as an unaware Oprah continued to explain her former humiliation -- Sidney himself walked out onto the stage.

"No, no, no, no, no, no, no!" Oprah exclaimed as she turned to see her idol standing before her, shaking her head in disbelief. "I'm shaking!"

Sidney, the embodiment of eloquence and dignity, then proceeded to read a passage he'd written to celebrate Oprah's 20th anniversary, leaving the shocked host visibly trembling as tears streamed down her usually composed face.

#5 - Mackenzie Phillips' Shocking Incest Allegations (2009)

When Mackenzie Phillips decided to come forward with claims she had engaged in an incestuous relationship with her father, Mamas & Papas musician John Phillips, it was Oprah she turned to.

"I woke up that night from a blackout and found myself having sex with my own father," Mackenzie read aloud from her book, "High on Arrival," during the shocking hour-long interview.

The former "On Day at a Time" actress said she was 17 or 18 years old the first time she remembers allegedly having sex with her father, and when she confronted him about the alleged rape, Mackenzie told Oprah he responded with puzzlement.

"'Raped you? Don't you mean when we made love?'" she recalled, of what she claimed was her father's response. "I thought, wow, I'm really on my own here."

As the disturbing interview continued, Mackenzie claimed her father had talked to her about running away to Fiji and living "as man and wife."

However, the final straw in the alleged relationship, Mackenzie claimed, was when she found herself pregnant and wasn't sure if the father of the baby was her then-husband, Shane Fontayne, or her own father.

#4 - Whitney Houston Admits Drug Use (2009)

Following years of drug rumors and speculation (and her infamous 2002 interview with Diane Sawyer where she flatly denied drug abuse by hoarsely uttering, "Crack is whack"), Whitney Houston kicked off what was intended to be a monumental comeback with a two-part interview with Oprah.

The "How Will I Know" singer laid it all on the line, admitting to "heavy" drug use - specifically a dangerous combination of marijuana with rock cocaine.

"You put your marijuana, you lace it, you roll it up and you smoke it," Whitney explained to Oprah.

The now 47-year-old superstar also claimed her ex-husband, Bobby Brown, had been very emotionally abusive toward her during their marriage (he allegedly spit in her face once, leaving Whitney "very hurt, very angry"), but only physically abusive on one occasion.

"He slapped me once, but he got hit on the head three times by me," she told Oprah.

#3 - Kirstie Alley's Brave Bikini Reveal (2006)

A "Fat Actress" no more! Fans still remember the day Kirstie Alley - at age 55 -- came struttin' out for all to see (to the Commodores' oh-so-appropriate hit, "Brick House"), rocking a maroon bikini in 2006.

The 5' 8" former "Cheers" star celebrated her 75-pound weight loss with Oprah, telling the host, "We can decide to change anything -- at any age. What I hope for all women is they feel good about themselves, they look the way they want to look."

Unfortunately, Kirstie gained all of the weight back (and an additional 8 pounds) in the years following her bikini debut, and returned to chat with Oprah in 2009 about her diet difficulties.

"I just sort of went wild," Kirstie told Oprah, before stating that her "food demons" included Chinese food, sugar and butter.

Despite the seemingly humiliating situation, Kirstie managed to keep it light (in true Kirstie-style), by announcing a tryst with a certain high-profile actor could make her feel sexy again.

"I want a booty call with Jamie Foxx. For real," she told Oprah. "I've always had a bit of a thing for him... I feel like he would understand the full-figured woman."

#2 - Michael Jackson Talks Sex & Skin-Lightening (1993)

When Oprah sat down with Michael Jackson for what would prove to be the most-watched interview in TV history at the time -- with a record 90 million viewers watching worldwide -- she asked him the question that was on the mind of many a pop fan, but no one wanted to actually voice.... "Are you a virgin?"

"I'm a gentleman," the King of Pop answered during his first interview in 14 years, dodging the pointed question. "That's something that's private, that shouldn't be spoken about openly. "

During the February 1993 interview, filmed months before he made headlines when authorities investigated child abuse allegations, Oprah also tackled the subject of the pop star's ever-lightening skin - prompting Michael to reveal he suffered from vitiligo - a condition he claimed runs in his family.

"It is something I cannot help. When people make up stories that I don't want to be who I am, it hurts me," he said at the time. "It's a problem for me. I can't control it. But what about all the millions of people who sit in the sun to become darker, to become other than what they are? Nobody says nothing about that."

#1 - Tom Cruise Couch Jumps For Katie! (2005)

The moment that had a nation of Oprah fans tilting their heads in collective confusion: Tom Cruise's lovesick couch jumping!

In 2005, Tom was head over heels in love with Katie Holmes, and while talking about the actress with Oprah, the superstar couldn't contain his excitement. He stood up, moved about and gestured wildly, before finally jumping up and down -- complete with clenched fists -- on Oprah's new couch.

The sudden outburst left the veteran host momentarily speechless before she abruptly declared, "You're gone. You are gone!"

During a subsequent appearance on "The Late Show with David Letterman," Oprah defended Tom, saying, "I don't think he's nuts. I had never seen him that way before... I think that that's what love does to you when you're just all impassioned, but I do have to say I was really surprised by it."