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.

“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.

David Jason’s toby jug of a face has been on the television screen over Christmas since the days when you had to get up and switch between three channels by hand. There was nothing ostensibly seasonal in his latest vehicle. A Yuletide entertainment for our times, Come Rain Come Shine had starring roles for three very contemporary ghosts of Christmas Present - belt-tightening, debt and social implosion. But scratch at the surface and what emerged was a neat inversion of the Scrooge tale, in which it was a big spender rather than a miser who had to learn the value of family.

Once upon a time, just before Lord Reith began permanent rotation in his place of rest, there was a hideous botchjob of a television genre known as the docusoap. It wasn’t quite documentary and it wasn’t quite soap. It was scriptless drama with “characters” whose “narrative arcs” were tweaked and massaged into what you'd loosely call "stories" in post-production. The docusoap launched the idea that the public will gladly work on television for sweet Fanny Adams. If there’s one thing you can applaud reality TV for – if there’s just one thing - it’s that it pulled the trigger on the docusoap. So it’s not quite clear what The Savoy is doing on ITV1.

Last week I suggested that The X Factor's rules may have been manipulated in order to lead to a more entertaining final week. I would like to apologise unreservedly for this suggestion, in the light of the absolute unremitting shower of dismalness that we had to sit through this weekend. Congratulations to the winner Matt Cardle and all - he seems like a nice chap, sings well sometimes, might even make a career of it – but sweet baby Jesus on a bendy bus, that was truly awful television.

And so we reached the climax of Series 7, long awaited by cognoscenti but greeted with mounting apathy by non-believers. Though some had held out hopes for boy - infant? - band One Direction, it was live poll favourite Matt Cardle who ultimately romped home to victory.

Even as a confirmed fan of the soap, I would be lying if I said I tuned in to Coronation Street for great acting. Fantastic comedy, yes; brilliant writing - certainly. But routinely fine exposition of the dramatic art? Nah, although there are honourable exceptions when the occasion demands. But by crikey, did most of the cast pull it off last night in an hour-long live episode to mark the show’s 50th anniversary, part of a week entitled “Four Funerals and a Wedding”, involving a gas explosion, a tram crash on the iconic viaduct and an attempted murder.

To vajazzle or not to vajazzle; it’s the question on everyone’s, er, lips. Thanks to ITV’s unlikeliest of hits, The Only Way is Essex, tans will be brighter, teeth whiter and bodies more diamante-encrusted across the nation this winter. It’s the aesthetic equivalent of missionary work, and boy are these guys devout.

Defying predictions that there would be no audience for a period costume drama set in an Edwardian country house, Downton Abbey has become the TV event of 2010. Episode one notched 11.6 million viewers (including repeats and ITV Player viewings), while episode two edged up to 11.8 million.