When We Were Kings (1996)

When We Were Kings (1996) stands as the most culturally resonant sports documentary ever made. Leon Gast's 22-year labor captures the 1974 Rumble in the Jungle, where Muhammad Ali's genius outshone George Foreman against the backdrop of Mobutu's Zaire. The film won the Oscar for Best Documentary Feature, a feat only matched by 3 other entries on this list. It earned $12 million at the box office, a remarkable figure for a documentary in 1996. The event itself drew 60,000 spectators and remains the 20th century's most significant sporting affair—outperforming #7's cultural impact by blending politics, music, and race into a single, unforgettable narrative.