Angelina Jolie has topped a poll of the best celebrity do-gooders of 2007.
The actress was voted the most respected celebrity humanitarian of the year for her work as a United Nations (UN) goodwill ambassador as well as being praised for her efforts to publicise suffering in Africa.
An online poll of 606 people, carried out by the Reuters news agency, put the Tomb Raider star ahead of U2 frontman Bono, Archbishop Desmond Tutu and Microsoft founder Bill Gates.
Peter Walker, director of the Feinstein International Famine Centre at Tufts University, commented: "People aren't stupid. They can really sense when it's just an endorsement and when somebody really means it.
"Someone like Angelina Jolie comes across as having more integrity than some celebrities and a greater sense that she doesn't just do this for the publicity."
Jolie became an ambassador for the UN High Commissioner for Refugees (UNHCR) in 2001 and has visited more than 20 humanitarian hot spots during her tenure.
"She does this in a very low-key way," said UNHCR spokesman Peter Kessler.
"She goes out to see for herself, to get up close and very personal. She doesn't travel with film crews, and I think that is real testimony to her dedication to the cause."
Meanwhile Madonna was voted the least respected celebrity altruist of the year, despite having raised millions for orphans in Malawi, after being accused of circumventing official channels when adopting David Banda.
"Madonna seems to do philanthropy the way she's done Indian culture, sex, and just about everything - like a disposable fad," one voter said. "Hope she doesn't get bored of her adopted African kid."
Paris Hilton finished second, after her aid trip to Rwanda was postponed while Bono and Oprah Winfrey also finished in the top five of the least respected celebrity do-gooders.