Most Underrated Biopic you know of

For me, it's Oliver Stone's "Heaven & Earth". Unlike most of his films, it's mostly about a young woman as she grows up. According to this film (based on her memoirs), Le Ly was raised in Vietnam and when the war broke out, her life was forever changed. After enduring horror and pain in Saigon, she eventually married an American soldier and went to America, where she raised her children, and against the odds, prospered. She never forgot her roots and went back to show her sons what it was to be who they were.

The film shows all of this, and more, with no shying away from the brutality that both the American invaders and the Viet Cong placed on Vietnamese people who wanted nothing more than to provide for and raise their families. The film features one of the best performances by an actress that I've yet seen. And that's saying a lot considering this was Hiep Thi Le's first acting performance ever. The film follows her brave struggles to survive, and does a good job of honouring the Vietnamese side of the Vietnam War. Why this was not received with the attention it deserved is beyond me.