GOODBYE GAZZA, farewell Geri. Icon that is born of media is of few days. It cometh forth like a flower, is thrust under everybody's noses until they can take no more, and is cut down: it fleeth like a shadow and continueth not. And it may be that the 23 episodes of the American comedy import Ally McBeal (Channel 4, Wednesday) will tell us whether or not the 30ish-single-woman cult continueth, or whether it fleeth. And for my part I hope that it fleeth. Because, just as the New Lad stereotype affixed itself like a succubus to Nick Hornby's success and gradually drove us all bonkers, so the Bridget Jones thing is now causing death by a million columns.

This is not, I suppose, Ally McBeal's fault. The Yanks hadn't even heard of Bridget Jones at the time that this show was commissioned (though they sure as hell have now). But one presumes that the producers were responding to a similar set of demographics and - let's be frank about this - advertising research studies. For once, therefore, we Brits defined a social trend first. And so Ally McBeal arrives here, feeling as fresh as yesterday's knickers.

Not that there is anything much wrong with it as a comedy. Calista Flockhart (a name I intend to give my family's first hamster) is a nice actor with an expressive face. Her ensemble - a black flatmate and an office full of lawyers - isn't bad either. Particularly good inventions include Elaine, the super-efficient secretary whose head balloons when she is being over-zealous ("I've programmed your speed-dials"). And I like the monomaniac ethics-free zone that is Ally's boss, Richard Fish - interestingly, his single-minded and amoral pursuit of profit is rather approved of.

The famous FXs, such as real arrows in the chest when the old flame turns out to be married, or the nude session in a cappuccino cup when he suggests coffee, are neat, if inconsistently generated. But on the whole, it had the same kind of adventure and risk as those recent Kotex (or are they Tampax?) adverts, in which lissom girls enjoy frenetic partying and hang- gliding, despite it being that time of the month. So, in Ally McBeal, lovely women with impossibly lustrous hair swapped mentions of yeast infections, ovulations and womanly cycles.

Oh, but so what? This Ally has it all, except the right man. She is beautiful, witty and intelligent, she effortlessly holds down a well-paid and demanding job, and every guy in the whole of Boston fancies her. Yet we must endure an impossible, self-pitying and tedious romanticism on our heroine's part. Well, I'm not saying that it isn't so in real life, and that Britain isn't stuffed to the gunwales with unhappy girls who have sod-all to be unhappy about. It's just that these women seem to care too much about themselves for me to care much about them. The moment has passed. It hath fled.

If I am out of sympathy with Ally, I have lost touch altogether with Friends (Sky One, Tuesday). Since they dumped us dishless folk to take the Murdoch shilling, I have failed to follow developments. So the arrival of the tape in which Ross is due to be married in London to someone other than Rachel, was an exercise in catch-up. The biggest bit of which was discovering that Phoebe is about to give birth to twins that she's carrying for her kid brother and his elderly wife. No, that's wrong. The biggest bit was discovering that Friends has metamorphosed into The Monkees, except without music. Chandler and Joey loose on the streets of London must count as the most Sixties retro thing that I've seen on telly in a decade. It was dire.

I don't, however, share the sense of shock expressed by other critics over what this tells us about how the Americans see us. It seems to me that Friends took us Brits entirely at our own comic recognisance, with Tom Conti and Jennifer Saunders (and Fergie for that matter) playing roles that they have portrayed in our own shows a million times. Indeed the best put-down lines were given to Hugh Laurie, sitting on a Virgin plane next to our Rachel. In fact, Laurie and Jennifer Aniston were good enough together to suggest a promising remake of A Touch of Class (although, in the end, all we got was a re-run of Four Weddings).

Now the week's big debating point. Was it just a terrible accident, or was it a carefully constructed conspiracy? Take what is just about Britain's foremost independent production company, add a well-respected veteran ITN reporter, and give them - as an executive producer - one of Britain's most up-and-coming young programme commissioners. You'd expect something solid, wouldn't you? But when the result is a pile of meretricious and manipulative shit, well - frankly - you smell a rat.

Diana: Secrets of the Crash (ITV, Wednesday), was made by Fulcrum, reported by Nicholas Owen and execed by my old colleague Steve Anderson. It claimed that there were a series of newly revealed unanswered questions about the car crash last year which, together, might add up to a case for there having been a conspiracy to kill Diana - most probably (it implied) by the British Establishment.

I won't dwell on the colour-supp access to Dodi's apartments, and the privileged relationship the film-makers appeared to have with Mohamed Al Fayed. These were not the show's true faults. No, what made this programme truly disgraceful was the elevation of tittle-tattle to the status of evidence, of the most far-fetched speculation to the status of theory, and of dubious attention-seekers to the status of reliable witnesses.

One example will suffice. The fatal driver, Henri Paul, had more money in his bank accounts than might have been expected (though not that much). Where had it come from? A friend of his, a Monsieur Garrec, told Owen that Paul "had contacts with the French secret service. That's all I know." He had no idea at what level or how extensive these contacts might be. So, on the basis of this flimsiest of testimonies, Owen put it to Fayed (who has been peddling the conspiracy account himself - an account that lets him off the hook) that "we know that he [Paul] was in touch with the intelligence services." Fayed sighed deeply over the wickedness of mankind. But we didn't know any such thing. All we knew was that Garrec had told Owen that Paul had told him that he was connected to the French secret service.

Owen and Fulcrum had no developed theory of their own. To have had one would have exposed the ludicrous nature of the conspiracy approach. So they did the old "more questions than answers" trick, thinking up as many unanswered questions as they could. But actually, of course, there are plenty of answers. So when Owen - an honest if limited man - says "the more I learn the less simple it becomes", we can read this as something of an admission. Though it doesn't answer my original question - what explains how this bad, bad film came to be made?

Windrush (BBC2, Saturday) by contrast was a good film in a good series, chronicling the recent history of West Indian Britain. Last night's episode took us from the Notting Hill riots of 1958, when white racists - urged on by the ageing Oswald Mosley - attacked West Indians, and left us in the aftermath of Enoch Powell's 1968 race speech.

One chap, Johnny Edgecombe, catalogued the Caribbean contribution: "We brought music, we brought colour, we brought dope, we brought life to this goddamn country." The volatile Edgecombe also brought a gun, with which he shot up Christine Keeler's front door. But his point remains sound. This country today is immeasurably enhanced by West Indian culture. But, oh, how much damage we did to the second generation of West Indians during the Powell period.

Given the importance of this combined lesson and celebration, it's a pity, really, that important stuff like Windrush languishes in the Saturday night schedules on BBC2, where the young people who don't know about it will never find it, while all the Diana crap plays at peaktime on weekday nights. I can only hope that this phase of marginalising the serious will soon flee like a shadow, and continue not.