Richard Zeisler ($100 million*)

A reclusive investor with a passion for art, Zeisler left his 20th century painting collection to the country's major art museums, including New York's Museum of Modern Art (where he had been a board member), the Metropolitan Museum of Art, the Guggenheim Museum, the Art Institute of Chicago, and the National Gallery of Art in Washington. His more than 100 works by such painters as Picasso, Miró, and Magritte were estimated to be worth $100 million. The Manhattan resident passed away in 2007 and had no immediate family. He had been heavily involved in the New York City artistic community, serving on the board of the Chamber Music Society of Lincoln Center, for instane, from its inception in 1969.