I'm not as familiar with South American literature as I am with literature from other Spanish-speaking regions, but two general suggestions might be Isabel Allende (Chile) and Gabriel García Márquez (Colombia). Allende is widely popular in English and Spanish and has some rather good books. Márquez is a Nobel Prize winner, of course, and while his literature might not be as accessible as Allende's, it's certainly interesting and worthwhile. You can find translations of Márquez in English, too.
One film I would HIGHLY recommend is "The Motorcycle Diaries" starring Gael García Bernal as a young Che Guevara. It's based on the book Che wrote about his travels with his best friend on a motorcycle around South America. The duo start in their homeland of Argentina (Buenos Aires!) and go through Chile, Peru, Colombia, and Ecuador for six months in 1952. The movie has absolutely beautiful shots of these countries, and I'm sure you would really enjoy seeing these places. Plus, it has a wonderful soundtrack composed by Gustavo Santaolalla as well as the Oscar-winning song "Al Otro Lado del Río" by Jorge Drexler. Incidentally, you can also read the book containing Che's writings in Spanish or in English if you can find it at your local bookstore.
Another movie you may want to consider is "Tango" directed by Carlos Saura and starring Mia Maestro. Personally I didn't care for it very much, but I don't think I was watching it very carefully. I do remember that it had some nice shots of Buenos Aires, though.
Some of the other MM'ers who have traveled to South America may be able to suggest some other books and films for you.