This post is part of our Money Face-Offs feature. Let us know who you think comes out ahead in this head-to-head match-up, and check out our other Money Face-Off posts.

Celebrities -- they're more than superior human beings, they're money-making machines. If these celebrities were stocks, which would be the shrewd buy?

One sure sign of celebrity is first-name recognition, and today's contestants have certainly reached that pinnacle. Oprah and Martha are brands known worldwide, Oprah for compassion and wisdom, Martha for style and elegance.

Martha Stewart's brand is still tainted by her 2004 insider trading conviction and her stretch in Camp Cupcake. Before then, her growth from model and stockbroker to America's favorite lifestyle celebrity was impressive. After authoring the bestselling book Entertaining in 1979, she transitioned to television with her hit show Martha Stewart Living, for which she gathered several Emmys. In 1987, she inked a lucrative deal with déclassé retailer Kmart as a lifestyle consultant, to help it break into higher price-point retailing. In 1990, with Time Warner (NYSE:TWX) she launched Martha Stewart Living Magazine. The zenith of her career came in 1997 when she took herself public. The IPO for Martha Stewart Living Omnimedia (NYSE: MSO) made her a billionaire.

This post is written as part of AOL Money & Finance's Best & Worst 2006. If you feel Oprah Winfrey makes too much money, cast your vote.

Multiple Emmy Award-winning host of The Oprah Winfrey Show, the highest-rated talk show in television history, Oprah Winfrey is also an Academy Award-nominated actress and a magazine publisher. Winfrey co-founded the women's cable television network, Oxygen, and is also the president of Harpo Productions.

Forbes recently estimated Winfrey's wealth at $1.5 billion, and has referred to her as the world's only black billionaire. She currently lives on a 42-acre ocean and mountain view estate in Montecito, California, and also has an apartment in Chicago, an estate on Fisher Island off the coast of Miami, a ski house in Telluride, Colorado, and property on Maui, Hawaii. Winfrey was called "arguably the world's most powerful woman" by CNN, and in 2003 she edged out both Superman and Elvis Presley to be named the greatest pop-culture icon of all time by VH1.