Philadelphia
Philadelphia wasn't the first movie about AIDS (it followed such worthy independent films as Parting Glances and Longtime Companion), but it was the first Hollywood studio picture to take AIDS as its primary subject. In that sense, Philadelphia is a historically important film. As such, it's worth remembering that director Jonathan Demme (Melvin and Howard, Something Wild, The Silence of the Lambs) wasn't interested in preaching to the converted; he set out to make a film that would connect with a mainstream audience. And he succeeded.