Good Artists?
It depends which context you are relating this too. Are you interested in How Spain/Latin America contributed to the art world, or how some revolutionized the way people perceive them through art?
Take a Look at these artists:
Diego Rivera - Social Realism
Francisco de Goya - Romanticism / (example of) Pre-Impressionism
Pablo Picasso - Cubism and (before 1907) - Expressionist
Frida Kahlo - Surrealism (and Personal Strife)
Salvador Dalí - Natural Surrealist
And these are only artists in the 20th century! There are still hundreds of years to sift through :)
But Personally, If I were to choose only one, It would be De Goya. He was arguably the first significant artist the popularized the romantic use of broad, rough brushstrokes that had never been used before in the sophisticated art world. He outwardly challenged the status quo with his release of works like "The Third of May, 1808." Then, in his later career, he became cynical and expanded his use of darker themes and imagery, which would now be coined as expressionism. He was a true revoluionary in the art world :)
Good Luck!