To name a few...
The adventures of Robin Hood (1938) with Errol Flynn, Olivia de Havilland and Basil Rathbone.
Adam-12
Dragnet
Most John Wayne Westerns, all the drinking aside, are usually pretty good.
One thing I find interesting about the old police shows is that the drug and crime problems, which were relatively new in the 50s and 60s and which the shows strove to blot out, only got a lot worse over time. I remember seeing a Dragnet where dogs were first trained to sniff out drugs from a warehouse, it was something never tried before and worked marvelously, they really thought they finally found a way to stamp out the importing of drugs.