How about something that tie's in with Standard Operating Procedure? Recent choices were pretty tame, do something that will generate lots of discussion and hate mail.
Top 5 POW would be good (Deer Hunter, Bridge to River Kwai)
Top 5 movies about terror and counterinsugency (Battle of Algiers, and the timeless Red Dawn)
Top 5 political films would also be fascinating (So many to chose from)
Sky is the limit.