Tony Manero (John Travolta) in "Saturday Night Fever" and Dirk Diggler (Mark Wahlberg) in "Boogie Nights" have one major thing in common: They both have posters of Al Pacino as Serpico on their bedroom walls. As the real-life NYPD detective whose integrity cost him virtually everything (and almost cost him his life), Pacino became one of the icons of gritty, realistic 1970s filmmaking. Released in 1973, between the first two "Godfather" movies, this is the true story of Frank Serpico, a long-haired, idealistic, iconoclastic cop who reluctantly goes undercover to investigate dirty colleagues who are on the take. This is one of the definitive Pacino performances, along with his role as Michael Corleone in the "Godfather" saga, and Sonny the bungling bank robber in "Dog Day Afternoon" (which reunited him with his Serpico director, Sidney Lumet)--and Pacino was nominated for a best actor Oscar for all of them (although he wouldn't actually win until 1992's "Scent of a Woman"). "--Jim Emerson"