Grand Splendid Ateneo

(Recoleta)
Address: Av. Sta. Fe 1860, C1123.

Housed in a former theater, gorgeous baroque style building. 

Eterna Cadencia

(Palermo)
Address: Honduras 5582, C1414BTM.

Indie bookstore. Great selection of books, trendy space, nice, relaxing café. 

Libros del Pasaje

(Palermo)
Address: Thames 1762, C1409

Also great indie bookstore located in Palermo. Great selection. 

Cúspide

Multiple locations. Its main location is in a shopping mall across from the Recoleta Cemetery. 

Librerías Santa Fe

(Recoleta)

Multiple locations along Avenida Santa Fe in Barrio Norte.