TV Guide Magazine is counting down the most famous and memorable moments on The Oprah Winfrey Show! Featuring new commentary by Oprah Winfrey and an interview with TV Guide editor-in-chief Debra Birnbaum, the series revisits the most unforgettable interviews, guests, performances and occurrences of the history-making show. Watch a preview! Then, tune in for the premiere Tuesday, August 28, at 9 p.m. ET/PT.