When I first started doing this site, many years ago, one of the many gaps in my education that I found was a knowledge of Spanish and Latin-American literature. Even though I read Spanish and was reading novels in Spanish, my knowledge was generally limited to the novelists of the Latin American Boom and a few classic Spanish authors, like Cervantes (portrait left), Lope de Vega and Lorca. I knew little about modern Spanish novelists nor much about non-Boom Latin American writers. I am fairly sure that most anglophone readers were in the same situation. I have since discovered that a) Latin American literature existed before the Boom and has continued to exist after it (see my site for some of them); b) that there are a large number of very worthwhile Spanish novelists (see my site for some of them). Thinking about this was prompted by my recent reading and review of Carmen Boullosa‘s El complot de los románticos [The Romantics’ Plot]. The book is about a group called The Parnassus, which consists of dead writers. Boullosa makes the point that Hispanic writers tend to be very much ignored in the English-speaking world.
My highly opinionated view is that many of the best novels of the twentieth century came out of the United States. This can be seen by the fact that the country with the most books reviewed on my site is, by far, the United States. 
However, I feel that this is changing and that the more interesting writing is now coming from Latin America and Spain. In her book, Boullosa laments the fact that a writer like Elena Garro (photo at right) has been almost completely ignored in the English-speaking world (including on this site, though that will change). She also makes a pitch for Jorge Ibargüengoitia, another writer who has been ignored in the English-speaking world (and on this site). While we are talking about Mexican writers, I would also make a plea for Hécto Camín and, of course, for Boullosa herself (photo below left). I am glad to see that I have thirteen writers on my Mexico page, though there should be (and will be) many more. 
Boullosa includes a bewildering array of Latin-American and Spanish writers in her book, including Borges, Bolaño, Estela Canto, Victoria Ocampo, Paco Urondo, Haroldo Conti, Bioy Casares, Ángel Rama, Marta Traba (wittily commenting that the latter two and Jorge Ibargüengoitia did not come by plane (all died in plane crashes)) and many others.
Writers such as Max Aub, Juan Benet, Camilo José Cela, Miguel Delibes, Carmen Martín Gaite, Juan Goytisolo, Almudena Grandes, Ana María Matute, Eduardo Mendoza (photo at right), Antonio Muñoz Molina, Carlos Rojas, Gonzalo Torrente Ballester, Esther Tusquets and Enrique Vila-Matas are virtually unknown in the English-speaking world and, in many cases, very few of their works have been translated into English. Carmen Boullosa definitely had a point about the neglect of Spanish and Latin American writers by the English-speaking world and it is hoped that it will soon be redressed, as it is realised that so much fine literature is coming out of that part of the world, but I am not counting on it.