That would have to be One Hundred Years of Solitude by Gabriel Garcia Marquez. What a profoundly human book. The kind of book that is very difficult to describe in any meaningful way, but which I unreservedly recommend to anybody.
Highly seconded.
This is a book about the Colombian Caribbean, but also the whole country and the region. At the end it is a book about life. I have always noticed that Anglo readers get too caught up on minor details (the number of Aurelianos, who did this or that) but that is missing the point, this is about the flow of life, the absurdity of human struggles, the magic and terror of being alive, love, senseless violence, hope, all of that expressed in a brilliant prose.
I could continue but this short youtube review has pretty animations and touches some other points: https://www.youtube.com/watch?v=B2zhLYz4pYo
The amazing video game "Kentucky Route Zero" is impossible to describe, but it touches on this genre in video game form and poverty in America with many references to this novel with characters named "Marquez" and so on. What an experience.