This week, an O-shaped hole opening in fans' hearts

LESTER HOLT, anchor: For 25 years, they have laughed with her and cried with her. This Wednesday is sure to bring many more tears as Oprah Winfrey says goodbye to her fans, bringing her show to a close. Tonight, NBC 's Mara Schiavocampo looks at how Oprah touched the lives of so many.

Ms. SAM SCARPACE: It's awesome, yeah.

MARA SCHIAVOCAMPO reporting: For Sam Scarpace , being a military wife meant moving often, but in every new city she found a familiar face.

Ms. SCARPACE: You spend a lot of time alone and you can either get in trouble or you can figure out how to entertain yourself. And my entertainment was Oprah .

SCHIAVOCAMPO: Every day Scarpace would turn to " The Oprah Winfrey Show " for friendship, comfort and guidance, a habit quickly picked up by her daughter.

Ms. SARAH McCRAW: It was an hour of tapping into pain that you didn't realize you had or helping you laugh about something that you didn't realize you needed a good laugh about.

SCHIAVOCAMPO: For millions around the world, the last 25 years have been about so much more than just a television show , connecting with viewers in a deep and personal way. From her home base here in Chicago , Oprah was able to start a national dialogue about topics so many were uncomfortable with, like racism, homosexuality and painful personal struggles. She also opened up about her own life. From her struggle with her weight to family secrets, creating iconic TV moments along the way.

Mr. PAUL LEVINSON (Author, "New New Media"): Oprah Winfrey embodies the last golden age of television talk show hosts.

SCHIAVOCAMPO: Last year when Oprah announced her show was ending, Sarah McCraw knew she had to be there, surprising her mom with tickets to a final taping.

Ms. SCARPACE: Oh my God! Oh!

SCHIAVOCAMPO: They went to Chicago together, joining more than 10,000 others at the United Center , including several celebrity friends.

USHER: Oprah has been an inspiration for all of us.

Ms. ALICIA KEYS: I love Oprah so much.

SCHIAVOCAMPO: Oprah 's not calling it quits. Viewers can still find her on cable's Oprah Winfrey Network , but their daily time together is coming to an end.

Ms. McCRAW: There will be a void because nothing -- this show was so special. There will never be another thing like it.

SCHIAVOCAMPO: A historic show built on a strong bond.

Ms. OPRAH WINFREY: My relationship with you is one that I hold very dear.

SCHIAVOCAMPO: One felt from both sides of the screen. Mara Schiavocampo, NBC News, Chicago .