The show runs the gamut from gossip to entertainment to health, frequently turning to personal revelations on the part of the host. One feature of the show, Oprah's Book Club made bestsellers of a number of novels and other works, including books by such writers as Isabel Allende, Joyce Carol Oates, and Toni Morrison. For several years the show featured segments hosted by Dr. Philip McGraw and more recently journalist Lisa Ling has appeared several times.
The show is known for every so often pulling stunts, with everyone in the audience leaving with one or several gifts. One of the most noteable ones happened on the 19th season premiere of her talk show (fall 2004), when Winfrey surprised 276 audience members with a free Pontiac G6 midsize 2005 sports sedan. Winfrey famously exclaimed, "You get a car! You get a car! You get a car! Everybody gets a car!" Although Oprah is often given credit for giving the cars away, they were donated to her by Pontiac as an advertising campaign.
In another famous Oprah incident, in April 1996, lobbyist Howard Lyman made remarks about Mad Cow Disease that led to Oprah's renouncing hamburgers. The National Cattleman's Beef Association sued Lyman and Winfrey. After a trial in Texas, both were found not guilty of any wrongdoing early in 1998.
--wikipedia