The Sword and Laser discussion

Ever since movies and series like Star Wars (planet Coruscant) , Star Trek, and even to some extent in the matrix (specifically when they when back to Zion) I have been looking for a book set in a over populated city where crime is rampant and the world is practically a cesspit full of decrepit rusting buildings. If you have any suggestions I would value them greatly. But feel free to leave recommendations for this genre as I (and many others) are avid Sci-fi readers.