Stuff you probably know already, Joel, but Elba, like many black British actors, had to become a name in US tv show/film before getting that lead BBC role. Lennie James also springs to mind. There might be exceptions, and yeah, they did UK stuff before (you should check out vampire drama Ultraviolet
), but the bandwagon seems to roll once they get that US hit.
's also interesting as it seems on surface a conventional urban British cop/detective series, but imo is closer to Life On Mars as a slightly bonkers psycho-drama. At least that's the only way it works for me