'Dog Day Afternoon' Director: Sidney Lumet (1975) 

The extraordinary true story of a bank heist that turned into a media circus/public event on a hot and sticky New York afternoon. Funny, poignant, tense and sometimes absurd but always rooted in a shared, flawed humanity. The characters may sometimes act in unexpected ways but they are always believable. Al Pacino, John Cazale and Chris Sarandon lead a uniformly excellent cast.