One of British TV's favourite themes is Britain itself. We're endlessly curious about the way things are for us now and about how we got here. In the most extreme sense, this led to the reality television boom of the noughties, but if you look elsewhere in the schedules - to drama, comedy and documentary - you find shows upon shows that actually don't stretch very far for their material. Stay local, that's our motto. Or maybe (if I wanted to sound a bit cool, which doesn't really become me): keep it real.

While it's becoming a challenge to find a new American drama that doesn't smuggle at least a small element of sci-fi into the goings-on, even if that show is generally billed as a quirky comedy-drama (see Being Erica), mainstream British telly is almost incapable of basing a drama on an unrealistic scenario.

So curious are we, still, with what is already there, that it will take us ages to reach the stage at which it will be commonplace to leapfrog over the issue of reality and go to that very American question: "what would happen if ...?" TV over here is just not particularly bewitched by the notion of possibility. We prefer to dredge up our old triumphs, mistakes and oddities, and chuck them on the tellybox for our twisted entertainment.

New drama abounds in our schedules this week and, sure enough, it's all rather brilliantly close to the bone. Sharp political comedy The Thick Of It (BBC2, Sat) continues after a cracking opening to series 3 last week (there's been much debate over which series we're on; this is series 3 if you count the specials as the second) shining an uncompromising light on government spin doctoring through the creation of a set of fictitious characters very similar to those who actually sit in Westminster.

In this second episode, "thin, white Mugabe" Malcolm Tucker (Peter Capaldi) continues to hound new DoSAC Secretary of State Nicola Murray (Rebecca Front) as she flounders in her newfound public attention. The writing probes into every dark corner of life as a minister, from last episode's issue with Murray's allegedly too luxurious lumbar support office chair ("Apparently, if you have a nice chair it turns you into Saddam Hussein.") to this week's more serious panic over the deletion of some extremely important immigration data.

More than anything, The Thick Of It is about the tiny details that make up a character. Tucker is dominant, of course, being "the all-swearing eye", the only character in television who can make swearing feel like a literary mode of communication, but Terri (Joanna Scanlan) had an excellent first episode, too. A high point of hers was her awkwardly keen contribution to the discussion over which signs and billboards ministers should never be positioned in front of at PR events, in case the press crops the text in the photograph into front page fodder: "Do you remember that folk singer Tim Hardin? Well ... you'd be able to get ‘I'm hard' from that..."

We don't need reality TV to illuminate reality, past or present. Creative writers can do that so much more effectively and entertainingly. Enter Garrow's Law: Tales From The Old Bailey (BBC1, Sun), starring Andrew Buchan (The Fixer) and Alun Armstrong (New Tricks). This series dramatises real legal cases heard at the Old Bailey in the 18th century and brings to our attention William Garrow, a brilliant defence lawyer whose skills of cross-examination are notorious and credited with much of the standards of contemporary court hearings. Grubby London, maverick lawyer, quick dialogue, historical accuracy. We like.

Later, do give The Family (Channel 4, Wed) more than a second glance because, contrary to popular perception, this is not - repeat not - a reality television series. Do you hear? The creators and directors are insistent that this be considered a documentary. A few years ago I'd've queried such protestation, what with all the cameras, real people and all, but the whole concept of reality TV has changed drastically; now, there is more orchestrated emotional response, and far less improvisation in a reality show than there is in a scripted comedy drama or documentary. In this warped climate ‘reality', I can well believe that The Family, in which the subjects are left to just behave without being told to manipulate laughter or tears at every turn, shouldn't be counted in that genre.

This second series, following the example set by the turbulent Hughes family last year - ooh, that Emily, I could give her a good clip round the ear - stalks the Grewals, a British Asian family from Windsor who are on the verge of hosting a big arranged marriage. See? Britain is the big interest. Even in the programmes billed as fiction or documentary, we're essentially only having a look at life as our neighbours might be living it, or our politicians. Drama begins at home.

• Geek shows and movies on UK TV in the week ahead