Buenos Aires has produced a disproportionate share of the 20th century's major literature, and reading around the city before or during a visit is well rewarded.
Jorge Luis Borges — Labyrinths (1962). The essential introduction to Borges, collecting the stories and essays that made his reputation. Every site in Buenos Aires that Borges mentions in his prose — the South Side, the orillas (outskirts), the Library — gains texture once you have read him. He walked the city obsessively; his Buenos Aires is a city of mirrors, libraries, and dead-end alleys.
Julio Cortázar — Hopscotch (1963). Cortázar's great novel about an Argentine intellectual in Paris and Buenos Aires, told in a structure that allows (or requires) reading in multiple orders. Less documentary than Borges, more dreamlike, but the Buenos Aires sections are recognisably the same city — the cafés, the river, the particular quality of late-night argument.
Tomás Eloy Martínez — Santa Evita (1995). A novel about the posthumous travels of Eva Perón's embalmed body — a story that is also, literally, true. Martínez treats the historical facts as fiction and the fiction as fact; the result is one of the most illuminating books about Argentine political psychology and the cult of Evita.
Martín Caparrós — The Hunger (2014; trans. 2020). A work of nonfiction journalism about global food poverty that uses Buenos Aires as one of its central case studies. The Argentina chapters deal with inequality, the informal economy, and what it means to be poor in a country that is also a major food exporter.
V.S. Naipaul — The Return of Eva Perón (1980). Four essays including a long piece on Argentina written in the early 1970s that is one of the more devastating portraits of Argentine society ever written by an outsider. Naipaul's view is harsh but not unfair, and the portrait of the country's self-delusion and political violence has lost little of its relevance.