My two favorite films would be, the Usual Suspects, and an old 1941 film in black & white The Maltese Falcon, which just gets the nod from Casablanca.
I'm a great lover of the American history during the 1800's and the wild west, so I enjoy films like The Alamo and Gettysburg, I know they are not 100% accurate, well Gettysburg is very close, but they give a good idea on how it was. Fortunately I have been to both sites and Gettysburg was huge in size and most fascinating, could have spent another day there.