I'll give another vote for Lewis. One of the biggest attractions for me and my daughters is the interaction between Lewis and his DS Hathaway -- the "average copper" with good insights and his quiet Cambridge-educated sergeant. Perhaps even greater differences than between Lewis and Morse. And the sparks with the recurring police pathologist are enjoyable, too. Colin Dexter, author of the Morse novels, appeared in a couple of episodes, I believe.
An 80s-vintage ITV show I have a soft spot for is Dempsey and Makepeace. More cop show than detective series. A tough NY cop uncovers high police corruption, so he's placed in a police exchange program & sent to London. He's paired w/ an officer who is also a crack shot noblewoman. Think The Odd Couple meets Starsky and Hutch. Lots of action, the cultural, social, and sexual tension you'd expect, but also a lot of fun as I recall. Only ran a little less than two years.