Sidney Lumet was one of the greatest directors of our generation. He passed away leaving behind one of the greatest lists of serious and acclaimed films of any modern director. Lumet seemed especially adept at directing serious psychodramas according to some film historians and film critics. Some of his great film achievements include 12 ANGRY MEN, THE PAWNBROKER, FAIL-SAFE, SERPICO, MURDER ON THE ORIENT EXPRESS, NETWORK, DOG DAY AFTERNOON, THE WIZ, DEATHTRAP, THE VERDICT, and many more great films. If you can't find a Sidney Lumet classic you love among these films, then you just don't love films.
Some directors are a director's director. Sidney Lumet was a true classic director. A great man. He will be greatly missed. His family have our best wishes and prayers.