For literary value I'd go with "The City of Saints and Madmen," there's more voice and history in a few short bits of fiction than there often seems to be in some real places.

Not really a book so much as a long essay, but "The Metropolis and Mental Life" by Georg Simmel has both rich historical context (being written in the very beginnings of the 20th century) as well as plenty of still relevant insight into how the structure of the modern urban city has acted as a catalyst for building particular kinds of relationships between people and how those are contrasted against more traditional, rural lifestyles. I think a lot could be extrapolated from that document into how the internet and social media has further guided relationships and human interaction.