There weren't many duff notes in Friends, the slick NBC sitcom that ran and ran from 1994 to 2004 and, for those of us with homes full of teenagers, is still running and running. But one of its duffest notes was the casting of Helen Baxendale to play Ross's British wife, Emily. Nothing against Baxendale, but amid all that sassy American humour, she seemed as flaccidly English as a stale Rich Tea biscuit surrounded by freshly baked chocolate-chip cookies.

In fairness, that was kind of the point; we weren't meant to warm to Emily. And Baxendale, deliberately, didn't get many killer lines. But it wasn't just that; whip-smart, wisecracking American humour just doesn't sound right emerging from a British mouth. For the same reason, Daphne Moon (Jane Leeves) was my least favourite character in the otherwise sublime Frasier. It's not that British actors aren't capable of wonderful TV comedy, just that the dialogue in the best US sitcoms is rooted in New York-Jewish traditions of razor-sharp put-downs and one-liners. Think Woody Allen and Neil Simon. On British television, comic dialogue has a different rhythm.

Anyway, all of this brings me to Episodes, in which Matt LeBlanc (dim, amiable Joey in Friends) plays a heightened version of himself in the latest example of what is rapidly becoming a TV genre all of its own: celebrities indulging in a game of double-bluff with us, playing themselves as slightly more neurotic and prima donna-ish than they actually are, which of course suggests that they're not neurotic prima donnas at all. Steve Coogan did this beautifully in The Trip recently, as did Larry David in Curb Your Enthusiasm. In Episodes, it is LeBlanc's turn. He plays Matt LeBlanc, hugely rich and successful thanks to Friends, who to the horror of married British comedy writers Beverly and Sean (Tamsin Greig and Stephen Mangan) is cast as the lead in the US version of their hit UK show. They wanted their British lead, a fruity RSC type called Julian (Richard Griffiths). But they get LeBlanc.

So far, so good. It's a great idea, with great opening credits: a script flying from London to LA. And there are certainly precedents for television successfully turning a mirror on itself; The Larry Sanders Show of blessed memory did it exquisitely. Moreover, there's something painfully real about British comedy writers being lured to LA by the sweet blandishments of network bosses and the promise of a Spanish-style hacienda in Beverly Hills, only for the semi-detached back in Chiswick to seem even more alluring once the dream starts to sour. You should hear the British writing duo Laurence Marks and Maurice Gran, who did the whole hacienda thing, on the subject. Yet I find myself unable to give a fat thumbs-up after the opening Episodes, and the problem lies with Greig and Mangan, or at least with their script. In a British context, they're both terrific comic performers. Greig was pitch-perfect as the hapless heroine in David Renwick's wonderful Love Soup. But here, trading waspish one-liners in the land of Jack Benny and George Burns, they seemed out of place. And although that's the whole point - that they are out of place - they should at least be talking like Brits, not Americans.

Still, it's early days. I have a feeling that Episodes will get better the more LeBlanc gets involved. And there have already been some lovely gags, like the friskiness that gripped Beverly and Sean when they saw that the vast bath in their rented Beverly Hills home could easily accommodate both of them, only for it to wear off while they waited for the damn thing to fill.

Americans just don't get our comedy. Our irony, our laugh-at-ourselves self-deprecation, our way with a juicy double entendre. At least that's the slightly lazy premise at the bitterly amusing heart of Episodes (BBC2), which finds a pair of Bafta-winning British writers heading to Hollywood to create a US version of their pet project, only to have it hijacked by those insensitive Yanks.

If you can get over that self-satisfied bump - from Till Death Us Do Part to The Office, the Americans actually have a respectable record of translating our laughs to their market - Episodes is actually a sharp and slick take on how we British revel in our own inferiority complex.

As the married writing duo, played with neat mix-and-match timing by Stephen Mangan and Tamsin Greig, get swept off their feet by the American Dream, their cynical posturing looks like so much hot air. They want it - the fame, the money - and they want it bad. Only it would be gauche to say so.

You could tell this was a British series because the set-up - having Matt LeBlanc foisted on them as leading man when the part was written for Richard Griffiths in History Boys mode - took an entire episode. The Americans would have done it in ten minutes.

The US comedy convention of starting a new series with a double-bill would have been one well worth copying after endless trails teasing us with the presence of LeBlanc, complete with distinguished gent salt-and-pepper hair. He only popped up briefly at the beginning and in the trailer for episode two. It left you feeling a tad twisted and manipulated - rather like the writers we were supposed to feel sorry for.

Green Wing fans will be overjoyed to see Stephen Mangan and Tamsin Greig back on screen together. In this new series they are scriptwriting husband and wife Beverly and Sean Lincoln who get an irresistible offer to transfer their hit British series - Lyman's Boys - to the US.

The scene set in their new producer's office in Hollywood is a brilliantly crafted exchange of double-talk and flim-flam and you can bet it's based on bitter experience, tales of woe and the frustrations of talented Brits who've had to deal with knuckle-headed American TV bosses. The star of Lincoln's show - set in a boys' school - is venerable British actor Julian Bullard played by the stout and silver-haired Richard Griffiths. By next week, he'll have been recast as his polar opposite.

This first episode is enjoyable if not quite as laden with zingers like Glee. But if it's a hit, it makes you wonder how the US version of Episodes might turn out.

An Anglo-American coproduction between stalwart British comedy outlet Hat Trick and acclaimed US writers David Crane (co-creator of Friends) and Jeffrey Klarik (Mad About You), Episodes is something of a curate's egg.

The inherent problems of transposing British comedy to an American setting are directly confronted within the premise of the series itself: terribly postmodern.

Former Green Wing co-stars Stephen Mangan and Tamsin Greig play successful married screenwriters whose award-winning sitcom is picked up by a powerful American network.

Whisked over to LA, they're shocked to discover that their quintessentially British series starring Richard Griffiths (who cameos as a version of himself) as an "erudite, verbally dextrous headmaster of an elite boy's academy" has been recast as a vehicle for wholly unsuitable Friends/Joey star Matt LeBlanc (also playing himself, inevitably as an egotistical buffoon).

Evidently aware of the ignoble tradition of point-missing American adaptations of great British comedies (Fawlty Towers without Basil? Why not!), Crane and Klarik have devised a sporadically amusing if rather obvious satire encompassing all the usual targets and stereotypes.

The Brits-out-of-water are cute and witty, the Americans shallow and crass. TV executives are liars.

Actors are self-absorbed. And despite protestations to the contrary, Hollywood just doesn't "get" British humour: the clever irony being that Episodes is written by a pair of witty American Anglophiles cocking a snook at the culture that made them millionaires.

The hollowness of the entertainment industry has been satirised so often, the curiously muted Episodes doesn't offer anything new. It feels like a missed opportunity, despite the odd bright spot and the natural chemistry between Mangan and the underrated Greig.

If a British sitcom gets better-than-average ratings, wins a couple of awards and isn't too downright weird to get lost in translation, it's not unusual for an American TV network to approach its creators with a mind to a Stateside remake. Probably the best known example of this is the American version of The Office, now in its seventh season, but the practice has been going on since at least the 1970s, when Steptoe and Son, rather surreally, was remade in Los Angeles as Sanford and Son.

What's little discussed, though, is how a behind-the-scenes collaboration between cynical British writers and hard-nosed US executives plays out - which is where this new sitcom, written by David Crane (Friends) and Jeffrey Klarik (Mad About You), comes in.

It stars Stephen Mangan and Tamsin Greig as a British husband-and-wife team who produce a successful show called Lyman's Boys, which is duly scooped up by a US network. They jet out to California and start working with their new colleagues, all of whom seem intent on stamping out any hint of fusty Britishness, starting with the show's corpulent lead, Julian (Richard Griffiths), whom they decide to replace with the wonderfully unsuitable Matt LeBlanc (Joey from Friends). The first episode is high on plot development and low on gags, but the series does improve and is worth sticking with.

Episodes, which got uproarious laughter in cut-down form at the Television Critics Association press tour in July, does not disappoint an ounce as it rolls through a seven-episode season. It also signals a savvy return to television for LeBlanc, who manages to be the butt of the joke one moment then hilariously likable the next. It takes confidence to play yourself but not really yourself and to know that moving past Joey and Friends means a simultaneous embracing/mocking of the legacy.

The premise of Episodes is simple (and all too real). Over-the-top, hug-happy, faux-sincere network president Merc Lapidus (John Pankow) meets the happily married writing team of Sean and Beverly Lincoln (Stephen Mangan and Tamsin Greig) right as they've snared a slew of BAFTA Awards for their (fictional) hit series, Lyman's Boys.

Lapidus loves the series and wants it on his network. He tries to woo the duo to the States, saying the show's perfect as is and would require a mere 20 minutes of their magic to make it Americanized. They can spend the rest of their time counting the money and screwing in the pool.

So they make the leap. And, not surprisingly, it's a long drop. Lapidus wants the British star of the series that has run for four seasons to audition - despite Sean and Beverly having told him he had the job.

Turns out, Lapidus doesn't watch much TV. "There's a chance that Merc might not have actually seen your show," says Carol (Kathleen Rose Perkins), second-in-command to Lapidus. "What?!" Sean and Beverly say in tandem. "I'm not saying he hasn't seen it," Carol says. "Has he seen it?" Beverly asks. "No," Carol says, shaking her head sadly.

And so it goes. Episodes was created by David Crane and Jeffrey Klarik, the writing duo that knows more than a little something about how the industry works. (Crane wrote for Friends, and Klarik wrote for Mad About You; both wrote for The Class.) There's so much delicious fun-house-mirror truth here. When the British thespian (played with gravitas by Richard Griffiths) does the audition, Lapidus and everybody else howls with laughter. They ask him to step outside for a moment, and Lapidus says, "Is it me or does anyone else think he comes off a bit too English?" They then make him read it again with an American accent. Nobody laughs.

Episodes might be inside baseball to some, but viewers are savvy enough about real-life industry types to get the joke. (God help them if they really were to see how shows evolve.) One of the sly bits in the series is Myra (Daisy Haggard), the head of comedy development, who has the same sour smile and confused look at all times - a visual joke that never fails.

Mangan and Greig are exceptionally good as the fish-out-of-water Brits, horrified that their show is getting rejiggered. Mangan's Sean is seduced by Hollywood, and Greig's Beverly is repulsed and appalled at the cluelessness. When the network hires LeBlanc to play the lead, Episodes takes off to all kinds of unexpected places - with LeBlanc getting a glorious showcase - and the show avoids any potential trouble spots.

In fairness, not every network would take a British series called Lyman's Boys, about a headmaster at an elite boys boarding school, and change it to Pucks! about a hockey coach at said school. But then again, one or two would. And that's all the truth Episodes needs to tap into.

Sick of living in squalor in Sixties Camden, down-on-their-luck actors Withnail (an impressively intense debut from Richard E. Grant) and Marwood (Paul McGann) decide to take an idyllic holiday in the Lake District. This superb British tragi-comedy, which has become a cult favourite, follows the two unemployables as they tackle extreme weather and Withnail's lecherous Uncle Monty (a typically imposing Richard Griffiths).