This seems to be about The Wire, and I'll write about that.
The Wire is from my perspective quite a bit different from the other top TV series that have emerged in this kind of "New Renaissance" period of high quality television (somewhat begins with Oz, but the hydrogen bomb explosion of quality was The Sopranos). What I think is different about The Wire is related both to why it's so uniquely great, and then also why I don't think it's as fully successful as a narrative work--and that last aspect is why I put it a few notches below the best ever made for the medium.
What made The Wire brilliant and so different is it examined the nightmare various cultural and government forces have created in American big cities, as an outgrowth of institutionalized racism over countless decades, doing this in a form that looked like a journalistic expose. This means while there were ongoing characters, their story arcs were not the point, and various people came and went in the whole scheme of the real focus. Even though there are prominent, very dynamic characters, like Omar for example, they are not the reason for the show. The show examines the devastation of the societal stratigraphy that is in place and never really dealt with by policing and politics. What the greatest art often does is show us something we have not seen, or fully understood, about our world, and that's the highest quality of this series.
This kind of free floating focus of characters and transient minor stories is why the show is generally acknowledged as having some weaker seasons and a meandering narrative focus, even while the spotlight it shines on the social engines that produce and fail to deal with inner city crime feel like they are on the level of the greatest video documentary journalism. I've been through the series three times over the years and the last time I felt it did not hold up as well as a great contiguous story, of following characters, while all the details (as you mentioned, acting, writing, direction) are superb.
