Oprah: The star has earned her reputation as a philanthropist and humanitarian, donating more than $50 million to charity, including a recent $1.5 million to Newark, N.J. public schools. (AP)
Bono: The U2 frontman has become one of the most famous humanitarian celebrities, working in Africa to help those suffering from AIDS, but also raising and contributing millions out of pocket and through various events. (AP)
Brad Pitt and Angelina Jolie: Brangelina has become synonymous with charitable work, with Pitt founding his own charity devoted to helping victims of Hurricane Katrina and Jolie working as a U.N. ambassador. Together, their Pitt-Jolie foundation donated $8.4 million to charity in 2008 alone! (AP)
George Clooney: The actor campaigns tirelessly to raise awareness on the genocide in Darfur, but his charity Not On Our Watch (NOOW) donated $500,000 in 2008 and $1 million before that. He also gave $25,000 out of pocket to the writer's strike in 2007. (AP)
Sandra Bullock: The star and her husband Jesse James have donated millions to the Red Cross and she has been honored by Glamour magazine for being an "undercover" hero. (AP)
Nicolas Cage: The actor donated $2 million to help former child soldiers, as well as millions more to Chrysalis and Amnesty International. (AP)
Will Smith and Jada Pinkett Smith: This Hollywood power couple donated more than $1 million to various civic, religious and art groups last year. (AP)
Jackie Chan: Assisted as a child by the Red Cross, Chan has more than given back, donating money to various charities including UNICEF and Chrysalis. He has also reportedly earmarked nearly $40 million of his fortune to be donated to charity when he dies. (AP)
Michael J. Fox: The actor, who suffers from Parkinson's disease, established the Foundation for Parkinson's Research, which has raised more than $140 million in research for new therapies. (AP)
Paul McCartney: The ex-Beatle donated millions to the tsunami relief fund, as well the Adopt a Minefield charity. (AP)