The Conversation, with Cindy Williams, Robert Duvall, Gene Hackman, John Cazale and Harrison Ford. In addition to this being a stellar cast in a very well made story with a big twist at its end, the jazz used as background is fantastic as well. I love the scenes--especially the close--of Hackman playing solo sax in the apartment he himself has completely demolished. Great stuff; too bad movies aren't made like this anymore!