the lives of others (2006)

aka Das Leben der Anderen.
"You don't know me, but I know you."
East Berlin in 1984, and a Stasi agent (Ulrich Mühe) undertakes covert surveillence on a playwrite (Sebastian Koch) and his actress girlfriend (Martina Gedeck). As he listens into their lives he finds himself increasingly drawn into their problems, and begins to compromise his position, as the writer begins to become disallusioned with life on the socialist republic, and determines to make a change.
A complex and involving subject, dealt with using an intelligent script and a deliberately slow pacing, building the menace and foreboding.