The most telling detail about the current state of TV drama is that, within living memory, it used to be habitual for the Brits to patronise American television fiction. The yanks were OK for glossy shows about cops with a distinctive physical characteristic – bald Kojak, fat Cannon, wheelchair-user Ironside – but the serious stuff was made here: classy costume dramas, the bold and campaigning Play for Today.

Viewers, reviewers and executives who remember when the phrase "wall-to-wall Dallas" served as a terrible warning of the possible consequences of the Americanisation of British drama regard the current era with astonishment. Now an envy of American television drama is one of the governing emotions at UK networks, while polls of the greatest ever shows are dominated by The Sopranos, Mad Men, The Wire, The West Wing and other awe-inspiring imports.

And, revealingly, the three most depressing aspects of our home-grown programming all stand in stark contrast to the situation in the US – under-representation of ethnic minorities, short runs, and uniformity.

Yet against these depressing tendencies can be set reasons to be cheerful about British small-screen fiction – including the joy of ad-free TV, the standard of acting, and hits such as last summer's Sherlock.