BritBox is a new subscription service for multiple platforms, including Roku, android, iphones, Chromecast, and many more. It's a collaboration between British broadcasters ITV and the BBC making a a wealth of British programming available in the U.S.
And this programming includes not just current PBS-type miniseries, but a huge catalog of programs going back decades. It includes ALL episodes of classic series from comedies like Porridge, Blackadder, and The Office to historical dramas like Sharpe's Rifles, Cranford, and Upstairs Downstairs to mysteries like Cracker, Morse, and A Touch of Frost.
It also includes ALL classic Doctor Who episodes, from the few still existing William Hartnell programs through all of the following incarnations of the helpful Time Lord, all of them beautifully remastered.
I do have to say that although the content is simply fabulous, the interface leaves a lot to be desired; navigation is difficult and finding the episodes you want cumbersome. However that's better than the reverse.
Here's a link to the website: BritBox