I love-hated Chinatown because the ending is so damn nihilistic. What are some other entertaining movies that have similar endings?

After seeing Monster 2003, I remember leaving the theater feeling gut-punched. After reading about the constant child abuse Aileen Wuornos suffered as a kid, it was hard reconciling the path her life took. Charlieze Theron did a masterful portrayal of a broken person grasping at straws for a bit of authentic compassion. It's no wonder Wuornos was such a mess.