Voice Of Post

As her show gets closer and closer to its finale, Oprah is looking back on some of the program's most memorable moments during its 25-year run.

On Friday, she revealed who her favorite guest of all time is: Dr. Tererai Trent, a Zimbabwean woman who, in Oprah's words, was "not allowed to have an education," was married at 11, had three children by 18, and whose husband beat her every day. Trent wrote down her dreams: to move to America and earn a bachelor's and a master's degree, as well as a PhD. She did every one of those things, and first appeared on Oprah's show in 2009. As Oprah welcomed her back on Friday, she exclaimed, "my favorite! Of all time!"

Trent told Oprah that she wanted to build a school in Zimbabwe, so Oprah surprised her with $1.5 million to help her out.

"We are going to build a school!" Oprah exclaimed.