As with pornographic films, what those who watch Glee really want is the money shot. There may be far fewer naked people – although the first episode of the second season did have lascivious shots of two shirtless (allegedly) teenage boys – but you still don’t really care about the bits in between the songs, which are all trite teen drama with a smart-mouth twist. No, the moment the plumber (geeky teenager) appears on the scene with his wrench (sheet music) is what gets the nerves tingling.

Few would dispute the supremacy of Cranford and Lark Rise to Candleford among the BBC’s current fleet of costume dramas. Measured, domestic and infinitely gentle, there are no Machiavellian footmen or illicit trysts here, just wholesome country adventures championing those unfashionable values of honesty, neighbourliness and hard work. The lamentable histrionics of the recent Upstairs Downstairs could have done well to note these successes, adapting material free from obvious drama (and in the case of Flora Thompson’s autobiographical trilogy, almost entirely without plot) and fashioning from it something credible and engaging. Lark Rise has its saccharine-sincere faults, but there’s no denying that with its characters back in the Sunday-night television slot, all somehow feels right with the world again.

What better to brighten our morbid January nights than the return of this superior Chicago-based legal drama? The Good Wife has never attracted lurid publicity or been afflicted with cutting-edge trendiness, but instead relies on the somewhat Germanic characteristics of being fastidiously designed and impeccably constructed.

There was always going to come a time when Little Britain had to stop. For a couple of years the heavily milked franchise seemed to be on a tape loop on BBC Three. Its international expansion - to the Greek islands one Christmas, to America for an entire series – suggested that its stars were getting itchy feet. That hankering to grow wings has manifested itself in the form of Come Fly With Me, a spoof docusoap in which Matt Lucas and David Walliams present an entirely new set of grotesques. In last night’s third episode, the gallery was still growing.

In 1994 half a million Rwandan Tutsis were slaughtered over a period of six weeks. Among them were the four brothers and two sisters of Jean-Pierre Sagahutu. His mother was raped before she too was killed. His father, a doctor, was intercepted on the way to the hospital and, when he was unable to pay a fine at a roadblock, was pulled from his car, hit over the head with a blunt hoe and taken to a ditch where his body was dumped. Rwanda, to which three million refugees have returned as the economy has tripled, is known as the great success story of Africa.

What’s with the two titles? A crime drama so good that they had to name it twice? Or couldn’t anyone in production decide which one to ditch? Why not swap them around, or maybe call it "Prime Suspect", or "Prime Suspect: Deadly Intent", or variations thereof? (OK, perhaps not "Prime Suspect: Above Suspicion", which would kind of cancel the other one out, but you get my drift.) Indeed, Lynda La Plante’s titles are so irritatingly, meaninglessly generic that they’d fit just about any old plot with a vaguely criminal theme. But then, her plots are generic, so I suppose as long as they’ve got cliché written all over them you’re OK, because at least then you’ll know what complete toss and nonsense to expect. And not even enjoyable toss and nonsense.

There must be good reasons why the fine crime novels of Michael Dibdin have been absent from screens large and small. They're probably to do with Dibdin's deadpan satirical tone and the anti-heroic nature of his protagonist, the Venetian detective Aurelio Zen. Also, his shrewd observations of the hidden undercurrents of Italian society are almost bound to get lost in screen translation. "Books and movies are completely different media", Dibdin once commented, "and the more the Hollywood crowd learns to knit their own stuff, the better."

All the time I was watching Toast last night, based on Nigel Slater’s memoir of his early years, I was wondering whether it was filmed for the benefit of the audience or of Slater himself. The final scene (no spoiler – we know how this story ends) where the young Slater ran away to join the kitchen at the Savoy was revealing: the head chef who gave him a job was played by Nigel Slater, reassuring his younger self that “you’ll be all right”. This felt more like therapy than drama.

“Television is pretty awful at the moment,” said Eileen Atkins the other week. “Is that because I'm getting old?” Age wouldn’t dare to wither Dame Eileen, of course, who has just bounced back in fine sparky fettle in the BBC's remake of Upstairs Downstairs.

If there’s one thing the British love on television at Christmas time, it’s a period drama, and even better, a period mystery. So what joy when there’s a bit of sleuthing by Agatha Christie's yin to Hercule Poirot’s yang, the eagle-eyed wise old bird Miss Marple, in The Secret of Chimneys.

Miss Marple (Julia McKenzie) is asked by Lady Virginia Revel (Charlotte Salt), the daughter of a dead cousin (what a lot of those the old girl appears to have), to be part of a lavish weekend party at the family’s country pile, Chimneys. The house was once known for its society gatherings until a rare diamond was stolen at a party in 1932, a theft that led to the end of Virginia’s diplomat father’s (Edward Fox) career.

The action starts 23 years on, when the world has changed and Chimneys is now too expensive for the family to maintain, but the ambitious and very dull politician George Lomax (Adam Godley) has offered to save it if Virginia, by some years his junior, accepts his proposal of marriage. Trouble is, she has just met and fallen in love with the dashing young Anthony Cade (Jonas Armstrong).

This being Agatha Christie (or at least a very loose adaptation, as she never appeared in the original story), those aren’t enough strands for us to unravel when someone is found deaded, in this case a mysterious Austrian Count (Anthony Higgins) who has specifically asked for a major international trade deal brokered by Lomax to be signed at Chimneys. There’s the chippy Miss Blenkinsopp (Ruth Jones), for one, from the newly created National Heritage who is very keen to get her hands on the property and is found snooping in the library; civil servant Bill Eversleigh (Mathew Horne), another would-be lover of Virginia; Virginia’s unmarried older sister, Bundle (Dervla Kirwan); and the family servant, Tredwell (Michelle Collins), who, Miss Marple soon realises, Has A Secret.

Chief Inspector Battle (Stephen Dillane) arrives from Scotland Yard to investigate and enlists Miss Marple’s help, but then two more deaths occur and lots of red herrings are released into this particular pond. The complicated plot includes a cache of love letters, coded messages, the cover-up of a death long ago and not one but two people with gambling debts.

As we eventually find the dastardly murderer, it all adds up to some nice light entertainment, of course, but by golly I wish everyone involved in The Secret of Chimneys could have given it even the faintest whiff of urgency. The feature-length episode was wonderful to look at, but I’m afraid both Poirot and Marple mysteries on ITV now appear to have taken over from The Bill as the common entry on all British actors' CVs; nice little earners where they galumph about pretty locations and spout trite dialogue as they wait either to be bumped orf or reveal the reason they committed the murder.

Few actors in The Secret of Chimneys appeared to have invested even a minimal effort in their characterisations. Edward Fox, we all know, has been playing variations on his most famous role, the Duke of Windsor, for some time now (the BBC missed a trick in not asking him to appear in the updated Upstairs Downstairs, set in the mid 1930s), Charlotte Salt’s accent was nowhere near posh enough (in contrast to Dervla Kirwan’s spot-on "frightfully"), Michelle Collins was miscast and, fine actress though she is, I think Julia McKenzie is too young and sprightly for Miss Marple.

Perhaps I spent too much of my youth reading Agatha Christie, but I remember her books being page turners; here the story dragged and by the end I didn’t care who had bumped off the Count. Full marks to the location, wardrobe and make-up people, however, as not a cuff or coiffure was out of place.