The Wire is very realistic, and also incredibly unrealistic.

I think it's important to note that while this show had probably the most detail oriented gritty realism in many ways, the show was absolutely thesis driven and essayistic. The purpose was often to make ideological and sociological points, as one does in an essay, rather than just portray things as they are in the day to day. The action, dialogue and characters were bent, either subtly or drastically, around the primary ideological points being made. Reality doesn't make clear, easy conclusions, with every system lining up in parallel to make perfect, expository points about the failures of bureaucracy. The characters that are not realistic side characters, or over the top caricatures (omar, mouzone), involved in moments primarily for dramatic effect, are often walking ideas. This is important to consider to recognize you could make other concepts drive a show in the same area, reality is multifaceted, and also to get the overall points of the show, which are poignant.

Note, this IS my favorite show of all time. But also seems to be the show ppl watch and think they know everything about inner city baltimore, rather than the perspective of largely two men (burns & simon), and another two men who are as close or closer to the same action could have an entirely different set of primary issues. If you study urban sociology & crime you will see paper after paper with different central theses as organizing principles to explain the violence, drug trade, schools etc. And each would make a different show that you could watch and just as much think "ahhh that's what the issue is!"