What is John Singer Sargent's most famous work?

John Singer Sargent's most famous work is arguably "Portrait of Madame X," painted in 1884. This striking portrait features socialite Virginie Amélie Avegno Gautreau, who was known for her beauty and fashion. The painting garnered significant attention for its provocative pose and Sargent's masterful use of color and light, though it initially faced criticism that led to Sargent's temporary retreat from the Parisian art scene. Today, it is celebrated as a masterpiece of portraiture and is housed in the Metropolitan Museum of Art in New York City.