Probably the most famous painting ever made is the Mona Lisa. Leonardo Da Vinci worked on this painting for four years.
Vincent van Gogh's most famous work, "Starry Night," is a good representation of Van Gogh's original technique of applying thick globs of paint.
Claude Monet's "Impression, Sunrise" was the basis for a new impressionist style. It was painted quickly and was used as inspiration for many other pieces of art.
Pablo Picasso's "Demoiselles D' Avignon," a very influential painting, spawned Cubism and was a precursor to modern abstraction.
Marcel Duchamp was the pioneer of Surrealism. His "Nude Descending a Staircase" is a good example of Surrealism emerging from Cubism and Futurism.
Andy Warhol's famous Campbell Soup paintings helped to make pop culture popular within the framework of visual art.