6. Dave & Shelly - Glengarry Glen Ross
Glengarry Glen Ross is a superbly prickly crime thriller, adapted to the screen from David Mamet's famous play by Mamet himself. Holding back on neither the play's acidic tone nor frightful use of profanity, the film revolves around a group of real estate workers who are faced with an ultimatum; start making real sales, or be fired. Led by the downtrodden Shelly (Jack Lemmon, in one of his all-time best performances), he and Dave (Ed Harris) plot to steal the new leads they were denied by their firm's higher-ups, and then sell them to the competition for a massive profit. The plan never really gets off the ground because Shelly is such a nervous wreck, and the office is under the watchful eye of John Williamson (Kevin Spacey), who eventually rumbles him. Still, even if they'd gotten away with it, when the stolen leads end up in the hands of their competition, the investigation is going to have a very limited scope of inquiry indeed.