Four Lions (2010), Directed by Chris Morris and written by Morris, Sam Bain and Jesse Armstrong.
Four Lions is a comic tour de force, which tells the story of a group of British jihadists who push their abstract dreams of glory to the breaking point. As the wheels fly off, and their competing ideologies clash, what emerges is an emotionally engaging (and entirely plausible) farce.
(video not working? - view here)