I'm surprised nobody has mentioned "Homicide: Life on the Street". Fantastic award-winning show set in Baltimore, with links to The Wire (writer) and Brooklyn 911 (Andre Braugher)...
Line of duty, earlier series especially. True detective, with woody Harrelson and Matthew McConaughey. Bit dark but very good. Good music aswell.
Surprised no one mentions Line of Duty given how recent it is. Not saying it is the best out there but pretty good all the same
Line of Duty disappeared up its own arse 2 or 3 series ago - full of plot holes and ridiculous contrivances. It's clear that the overarching plot was never planned from the start and the writer is just haphazardly bolting bits on.
CSI Dodworth. New drama featuring the debonair crime fighter known only as "Big Lil". Assisted by his enigmatic partner, Crystal, and his trusty rescue pooch, he specialises in complex cases involving memory loss, turnstiles, and bovril.