EXCLUSIVE: Oprah Winfrey Shares the Biggest Shock She Ever Had on 'The Oprah Winfrey Show'

Oprah Winfrey reminisced about 25 seasons of her iconic talk show in the new issue of O, The Oprah Magazine.

After walking away from The Oprah Winfrey Show in 2011, Lady O sold the Chicago studio where the production was shot and now you can bid on some of the items from the media mogul's closet on eBay.

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While sifting through the items, Oprah looked back on the show that made her a household name.

"Biggest shock I ever got, of course, while I was on the air was the Mary Tyler Moore surprise!" Oprah said, referring to the 1997 episode in which the TV icon paid her an unexpected visit on the air.

And who could forget Tom Cruise jumping on the couch?

"After Tom Cruise was on the sofa, people were asking me did I know he was going to jump on the sofa," Oprah said.

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As for her most cherished moment, Oprah gave that distinction to Tina Turner. In 1997, Oprah performed with the GRAMMY winner during her tour.

"I could watch me singing with Tina Turner -- 'Simply the Best' -- I could watch that over and over again, because that was truly a highlight in my life," Oprah said.

The new issue of O, The Oprah Magazine hits newsstands Feb. 16.