heartily agree with Crackerjack re the Corner, and i would endorse H:LOTS (although the last coupla seasons pretty much jumped the shark: also in some later episodes there was the odd regrettable bit of cross-over with Law & Order).
the latter very much a police procedural but tending to get a bit existential (there are certainly a few essays about this bad boy online).
TIME once noted
This deeply character-based police drama from Tom Fontana and Barry Levinson was notable for being a show where the murders were less important than the psyches of the cops who solved them (and sometimes failed to)...With an acute sense of the media, political and spiritual ramifications of crime, Homicide drew a broad picture of how many lives were changed when one is taken.
the Dostoyevsky to the Tolstoy of the Wire, if you will.
different sort of burn after the Wire or the Corner of course, back to the cops, but it could be funny, smart and affecting; notable for focusing less on gunfights, more on the weary work of clue-sniffing. it may seem a bit less full colour coming to it from the Wire granted, a bit meh.
though, FWIW, those two and the Shield are in my personal trio of top 'tec shows (or shows with some focus on 'tec, tbc) with early NYPD Blue and early Law & Order scratching at the door.
because of the same sort of stable, lots of actors from the later Bawlmer shows appeared here, eg an ME in the Wire is a major drugs don in H:LOTS (!), and Bodie the dealer shows up too, that sort of thing.
Clark Johnson is deeply entwined with the Wire and H:LOTS as well, acting a major role in both.
never read any of the books, no.
two bits that show its appeal (if you like this sort of thing), one episode has them sat in the squad room just chewing the fat for the duration, and then as the end credits roll, the hotline rings, just conversing for that ep.
another ep shows a real time hour of a guy who fell (or was he pushed?) onto the subway and he's got jammed between a train and the platform and not in good shape: the cops are there because it is literally a potential murder in waiting, it may be homicide/manslaughter when he goes, because of course it might not have been an accident that he ended up on the track.