Untitled by Felix Gonzalez-Torres
From the Art Institute of Chicago's web-page:
This installation is an allegorical portrait of the artist’s partner, Ross Laycock, who died of an AIDS-related illness in 1991. The 175 pounds of candy corresponds to Ross's ideal body weight. While on display in our contemporary galleries, viewers are encouraged to help themselves. As the pile diminishes, candies are replaced.
(Thanks for the photo, Penn)