Soul Music - people talk about what a particular piece of music means to them, with an expert talking about interesting things about the music itself and lyrics
Desert Island Discs - decades worth
The Life Scientific - eminent scientists interviewed
Private Passions (Radio 3) - higher brow version of Desert Island Discs with more music than talk
All of those have a huge back catalogue.
The next two will probably not be available for long because they were repeats for the VE Day 80th Anniversary.
https://www.bbc.co.uk/programmes/b010t6np Millions Like Us - interesting five part series about women's lives during WW2 (5 x 15 mins)
Coming Home - 5 episodes, around 45 mins each, made in 2005. I found this really compelling. Charles Wheeler (much missed) presents a compilation of interviews and archive clips about the lives of ordinary British people as WW2 came to an end and over the next few years. https://www.bbc.co.uk/programmes/p009x6m8/episodes/player
Born in Bradford - periodic programmes about a huge long-term research study following children born in Bradford https://www.bbc.co.uk/sounds/brand/m0001kbd
The Body Politic - three programmes presented by Sonia Sodha about contentious issues to do with the human body, e.g. surrogacy, end of life https://www.bbc.co.uk/sounds/brand/m0026v8h
In Dark Corners - Alex Renton looks at how paedophiles got away with their crimes over many decades - tough listen but very well put together, and absolutely enraging. https://www.bbc.co.uk/sounds/brand/m00272c7
More or Less - checks the accuracy of statistics mentioned in the news, far more engaging than it sounds https://www.bbc.co.uk/sounds/brand/b006qshd
File on Four - regular documentary programmes. All sorts of topics covered. This one was really, really good about the stages leading to Femicide: https://www.bbc.co.uk/sounds/play/m0029395