She may have gotten her start traipsing the art underground, arm-in-arm with Basquiat, but her art collection began on a highbrow note: In 1987, she shelled out nearly $1 million for Fernand Leger'sLes Deux Bicyclettes.
Since then, she has acquired more than 300 works, drawing from Modern masters -- Man Ray, Salvador Dali, Maxfield Parrish -- and the occasional contemporary one, a la Hirst. Fellow chameleon Frida Kahlo is a favorite, as is sultry portraitist Tamara de Lempicka. In 2000, Madonna paid $4.7 million for Pablo Picasso's Buste de Femme a la Frange, contributing to a 2008 appraisal of her collection of more than $100 million.
In May 2013, she put up one of her Legers -- the 1921 Trois Femmes a la Table Rouge, picked up at Sotheby's for $3.4 million in 1990 -- for auction, pledging that profits would go toward girls education in Afghanistan and Pakistan. It went for $7.2 million.