Generic futuristic cities. Generic futuristic cities often equals generic futuristic storylines.
A futuristic city is almost always portrayed as a metropolis, and small towns, countryside and villages seemingly don't exist anymore. Metropolises (metropoli?) come in only two flavours: the industrial, crime ridden dystopia, or the beautiful, superficially-utopian city which has a terrible secret and is hiding its dystopian elements in the closet with the skeletons.
These cities will usually be in the shit due to a single specific element, such as it is run by fascists, or it is plagued with dangerous androids, or the global environment is haggard. Thus, the solution to these one-note problems is equally as specific and straight-foward (kill the fascists, kill the androids, kill those who are killing the environment etc.). Often this requires a rebellion to do the job, often led by a person who worked for the government, but switches sides and takes up the cause.
Very few sci-fi cities avoid this type of classification. A decent future city is not an outright dystopia and does not have a single glaring flaw, but rather a number of complex issues which have to be juggled around and compromised over. A city in which a simple rebellion will not solve everything.
Ghost in the Shell is one of the few examples I can think of which does a future city correctly. Cowboy Bebop is another one, by virtue that there is no one left to blame for the sorry state mankind is in, and whilst humans live precariously, they do not live in an outright dystopia. Yokohama Kaidashi Kikou desesrves a final honourable mention by not including any cities at all, and by turning what should be a dystopia (a post-apocalypse in which man-kind is dying out) into a paradise (where one can run a coffee shop and gaze at the countryside all day).
