It is really hard to understand the British accent. I have a British teacher. He's married to a Singaporean girl who is bilingual. She grew up in a family that only spoke Chinese and went to school that is only English-spoken. She even went to university in Australia but she can't understand anything at all about the dialogues in British movies which my teacher watches in his free time. British accent is less common than American accent so I hope you know what you are up to.

Thanks a lot Dan. If you are going to provide a list of drama, maybe it is better you providing it as an answer, coz it can helps you to get italki points. although I don't know what's the use of these points, it is better than nothing.

I would maybe steer in direction of more present time BBC dramas. I can provide a list later. Downton is a great drama but time period is around century ago.

Thank you. I like the actors' accent in Downton Abbey, especially Mary. But I wondering whether the words they use and the ways they are talking are suitable for nowaday life?

Maybe 'Downton Abbey' would be a good choice.