Of course there are the old standards, like Shetland, Sherwood, Vera, Endeavor, Unforgotten, Broadchurch and so on, but I'm looking for some new ideas. Here are a few I've seen recently and enjoyed; mostly on BritBox or PBS; one on Hoopla.
MaryLand: An enjoyable PBS show about 2 sisters who discover their mother's secret life on the Isle of Man. I really want to visit there after seeing this show (which is worth a watch in its own right).
Blue Lights: Really good cop show shown from the viewpoint of rookie police officers that takes you into the heart of Belfast. I loved it! Britbox
The Marlow Murder Club: A new low-key mystery on PBS about 3 women who become involved in several local murders. Filmed entirely in Marlow (and now I have another place to add to my list of destinations).
QI: a wonderfully funny comedy quiz show with that typical British irreverent humor. It stars Stephen Fry, who was ultimately succeeded by Sandy Toksvig, and both of them are absolutely perfect!
The Tower: shows the politics of British police departments. I wasn't sure if I would like this but kept on watching, and really enjoyed it.
Annika: Another PBS show about heads a woman (Nicola Walker), who heads up the Marine Homicide Unit in Glasgow, tasked with solving murders in and around the Scottish waters.
Happy Valley, starring the wonderful Sarah Lancashire, about a female police officer in a small town in England.
Zen: Rufus Sewell stars as Italian detective Aurelio Zen in a series based on the best-selling novels by Michael Dibdin. It's actually set in Rome but the actors are British playing Italian characters (the same premise as Roger Allam in Murder in Provence). Really good and I love Rufus Sewell in this. I became enamored of him after watching him in The Diplomat on Netflix. It can be streamed on Hoopla.
I can think of more but would love to know what everyone else is watching and has enjoyed!