The Battle of Algiers by Pontecorvo.
So good, so realistic that it was used, in its entirety for instructional purposes in the JFK Special Warfare Center at Ft. Bragg and the Command and General Staff College at Ft. Leavenworth. The second time I saw it it was pitched to a short-course at Leavenworth and introduced by a French LTC who had not only fought in Algeria, but had been jailed for rebelling against De Gaulle (maybe he was in the 1st REP) and then rehabbed back into the French Army. Coincidentally, I just found this film on enhanced DVD last Saturday and picked it up. I strongly recommend it.
The Battle of Algiers (film - Wikipedia, the free encyclopedia)