Some discussion on earlier thread: T FOR TYPOGRAPHIC VENDETTA.

The poster uses Futura, which was not mentioned in the original thread.

(The "Lewis Prothero" image uses ITC Johnston, which was identified in the original thread.)

The cover of single-DVD release of the movie also uses Futura.

But strangely, the cover of the Two-Disc Special Edition DVD uses a completely different typeface: Konvexist-Alternate Oblique.

(See them both here).

Strange.

It isn't just the DVD cover. Futura is pervasive throughout the film (i believe intentionally so). Everything from the ending credits to the propaganda posters displayed on London's streets, from the curfew notices to the headlines and body copy of newspapers--every bit of type in the film is Futura.