Here are films that changed the world, righted wrongs, pinpointed a moment in history, or simply shone a light on a previously unknown subset of society. (Availability subject to change. Films are unrated, except as noted.)
1. "20 Feet from Stardom" (2013) PG-13
This Oscar-winning doc shines a spotlight on the relatively unknown backup singers behind such superstars as Bruce Springsteen, Sting, Mick Jagger, and Stevie Wonder.
2. "The Act of Killing" (2012)
The director invited killers -- men who took part in the horrific purge that left more than 500,000 dead in Indonesia in the 1960s -- to reenact their crimes on film, resulting in a bizarre look inside the mind of men capable of mass murder.
3. "The Battered Bastards of Baseball" (2014)
Two filmmakers pay homage to their grandfather,