If on a winter's night a traveler (1979)
by Italo Calvino
If on a winter's night a traveler is a fully post-modern novel in every sense of that phrase. Calvino using a framing narrative, switches between second and third person narrators within the same chapter, uses the "reader" as a central character and assorted other tricks which are central to post-modern literature. On top of that, the plot is a twisting, turning snake involving the attempt of the reader to read a novel which has been mis-translated, lost in the mail and may not actually exist. Near the end, he introduces the idea of a Japanese company constructing fake novels of an Irish author. There are also multiple instances of Calvino inventing languages, lands and peoples.
Obviously, If on a winter's night a traveler is confusing, but unlike other experimental fiction from this time period, at least it's fun. For me that, is the main difference between successful and unsuccessful post modern literature, the successful stuff is fun. After all, if reading a novel requires the level of concentration one typically uses for work, the text itself better not be dull.