I am a big fan of British tv from the 1960s and 70s, especially the series produced by ITC. You know, Danger Man, The Prisoner, Gerry Anderson stuff like Thunderbirds and Captain Scarlet, The Saint, Randall and Hopkirk (Deceased) and many more.
Some were better than others, but they all had a style that was instantly recognisable. There were so many good actors who appeared before they became famous, and a list of stock actors who had multiple roles, including George Murcell, David Bauer, Eric Pohlmann and Kenneth J Warren (look them up, you will recognise them immediately).
They series were actually made on film, so they have survived well to this day and look good. Cheap, but good.
One I remember was The Champions. The thirty episodes covered 1968 to 1969, and it has had repeats since.