My favourite detective series is Midsommer Murders (mentioned before, I know), shown every summer over here. I just love the concept of three murders, Mrs Barnaby or the daughter always aquainted with the victim or some of the suspects and no violence.
Where in Britain are the episodes filmed? Next vacation to Britain I'd love to rent a car and visit those beautiful villages.
Now there's another series to my liking: Mrs Marple, most likely the one Stepurhan mentioned. I've only seen one episode so far.