I don't think this has been mentioned yet - A Family At War (Granada, 1970-2), currently coming to the end of its' repeat run on Talking Pictures TV:
And, yes, the clever use of the sandcastle with flag - which presumably cost shillings to film, adds up to a very evocative opening.
I've always had a soft spot for the late Derek Hilton's theme to A Kind of Loving (Granada 19820, too.
Derek also did the stirring theme to The Spoils of War (Granada, 1980-1), which I can't find online now - and sadly no trace either of Nigel Hess's theme to A Brother's Tale (Granada, 1983 - and to my knowledge never repeated since - unless someone can correct me.)
Intelligent readers may have spotted a pattern - if it's Granada, and John Finch or Stan Barstow are involved, I'm all over it. This quartet probably makes up my top four list in tv drama - three of them were shown just as I was reaching the age to appreciate grown-up drama, and taught me at least something of what adult life was like.