"Daddy & Papa" (2003): Same-sex parenting as seen through the lives of four families led by male couples.

"February One: The Story of the Greensboro Four" (2005): The quintessential telling of the 1960 North Carolina sit-ins that inspired nonviolent protests across the nation.

"Enron: The Smartest Guys in the Room" (2007): A complicated financial scandal is boiled down to a universally understandable issue: greed.

"Wordplay" (2007): Bill Clinton and Jon Stewart are among the ink-stained wretches obsessed with the New York Times crossword in this love letter to puzzlers.

"Have You Heard From Johannesburg?" (2012): Five weeks that encapsulated the 45-year struggle of South Africa's anti-apartheid movement.

"Being Elmo: A Puppeteer's Journey" (2012): This touching biopic has been reassessed in light of allegations of sexual impropriety by performer Kevin Clash.

"Muscle Shoals" (2014): The tale of one of the unlikeliest music hotspots in history, an unpretentious Alabama community where such hits as "When a Man Loves a Woman" and "Brown Sugar" were born.

"Best of Enemies" (2016): Gore Vidal and William Buckley duke it out in historic footage that set the stage for every other show you see on cable news.

"Tower" (2017): Animation has rarely been as somberly applied as it is in this re-creation of the 1966 shootings by a sniper at the University of Texas.

"I Am Not Your Negro" (2018): Acclaimed author James Baldwin turned out to be just as fiery on camera as he was on the written page.