Just 5?
In no order at the moment--
X--I watch this film about once a year. When I read Spike Lee was going to direct it, I was initially skeptical. But this film has to be one of the best films he's ever done.
Bloody Sunday--I love the Irish and this fllick about the Irish civil rights movement is incredible.
All the Presidents' Men -- creepy film that gets creepier as the years pass by....and, this,the last time the people could boast about real investigative journalism (vs main stream media)
Reds -- sends chills down spine just thinking about it. Reed's passion couldn't exist in today's kind of activism--he'd be killed or set up
The Insider--the rise of the corporatocracy. Corporations still hire their Pinkertons to protect profits (other whistleblower films: Silkwood, Norma Rae, China Syndrome, Rainmaker
Matewan--scabs & coal mines
Others I like and could be up there, too: Syriana, Z, The wind that shakes the barley, Battle of Algiers, Bus 157, The Candidate, Manchurian Candidate (original), War Room, the Vernon Johns Story, King, Boycott, Missing, Taxi to the dark side....I'm sure there are more.
I've not seen The Deal or Street Fight; I'll find them.