The best dramatic film portraying the events of September 11, 2001 yet made is United 93, which Paul Greengrass made in 2006. But the best film, period, about 9/11 was made on the day itself by French documentary filmmakers Jules and Gedeon Naudet, who were in New York that Tuesday morning to shoot footage for their planned profile of a firefighter in training. One they got instead was a one-of-a-kind record of the World Trade Center attacks as they unfolded.
Embedded below, in six parts, is 9/11 as it was broadcast on CBS. You can watch it this way, or order the DVD of the extended cut. Either way, it is an amazing, wrenching, historic piece of filmmaking that everyone ought to see.