Only in my adult life did I read the stories, finding large chunks of the dialog in the TV show being word for word taken from the stories. And when not word for word, the tone and feel of the scenes so well portrayed on screen.
Yeah, I grew up watching that on PBS Mystery! and love it. I rewatched some of it as an adult and it holds up very well.
I also really liked David Suchet's Poirot. I still have yet to watch the last few seasons though.
However, I've never been much enamoured with the Miss Marple adaptations. Joan Hickson's is maybe the best (even though I prefer Geraldine McEwan as an actress) but I never took to it like Poirot.
You might like the nineties Jeeves and Wooster which stars Stephen Fry as Jeeves and Hugh Laurie (of House fame) as Bertie Wooster. It is formulaic but fun. I think it's the best thing Stephen Fry ever did.
There is a Soviet version of Sherlock Holmes which is surprisingly good starring Vasily Livanov. The locations sometimes don't quite look like England etc, but I really enjoyed it.
However, I do not think the BBC has provided a decent service to Scotland over the years at all. We tend to be represented in certain clichés, if we are represented at all. Another clip from the same era is basically about a Scottish drunk who cycles over the Lairig Ghru and back, and has a patronising posh voiceover the top.
The Baader-Meinhof series is good. I enjoyed the film they made about them some years ago. I was impressed by how nuanced it was, i.e. showing all the various angles.
There were some great period dramas at the time, if a little set bound (like I, Claudius)