I've said it before, and I'll say it again the Annihilation Saga
Annihilation (Season 1), Conquest (Season 2), War of Kings (Season 3), Realm of Kings (Season 4), and The Thanos Imperitive (Season 5)
Locke & Key.
Three siblings move to a giant mansion and discover that certain doors in the mansion have magical properties when opened with the right key. Now they have to figure out the mansions past while keeping the mysterious Omega key out of the hands of an enemy who might be closer than they realise.
This stuff writes itself!
I remember Compound had a great Daredevil tv pitch that felt like the first season would be "Daredevil begins" really exploring the mythology.Daredevil would be great, but good gravy,
Gotham Central would be award-winning, epic, and legendary.
Grim-and-gritty crime dramas seem to be a dime a dozen but add in the faintest hint of Batman involvement and a little bit of - what's the word - not "supernatural" characters or stories, but more extraordinary as would be the case with regular cops taking on parts of Batman's rogues, and the constant struggle with resisting and dealing with corruption...wow. It would be amazing.
Honestly, for a show like that the whole I'd just be thinking "I'd rather see more of Batman" because as you said cop shows are a dime a dozen so other than Batman there's really nothing that would draw me in. Even if Batman wasn't a part of it, as if it was a series based off the comic but not a direct adaptation. It would still sound like a cop show with a gimmick. I would love a miniseries though, but the longer the show goes on the less interest I'd probably get.