Ken and Lorna are two upstanding parents who want the best for their daughter so you can imagine their horror when she comes home from a gap year with a surprise husband - an idiotic American hippy - in tow. Helen Baxendale and Greg Davies (aka Mr Gilbert from The Inbetweeners) star in this promising new sitcom, with Saturday Night Live's Andy Samberg joining them as the antagonistic new son-in-law.

Chances are you won't know the star of this new sitcom, but Andy Samberg is well known in the US as a regular on Saturday Night Live and as part of the comedy troupe The Lonely Island.

Here he plays an American hippie called Cuckoo, perhaps not the last person on Earth you'd want your ­brilliant daughter to bring home from her gap year in Thailand, but not your first choice for ­son-in-law material, either.

Thanks to Samberg's subtly distracted performance, this is even funnier than it must have been on the page.

Cuckoo is new-age nonsense personified, but still cheesy enough to nick a chat-up line from Four Weddings and a Funeral.

Helen Baxendale and Greg Davies play shocked parents Lorna and Ken, with Tamla Kari as their smitten daughter Rachel and Tyger Drew-Honey from Outnumbered as Rachel's brother.

The scene when he ridicules Cuckoo over his name is even funnier when you remember his own name is Tyger.

New sitcom starring giant actor Greg Davies as patriarch Ken who is introduced to his new son-in-law Cuckoo for the first time in the arrivals lounge on his daughter Rachel's return from her gap year in Thailand. It's an understandable shock, particularly as Cuckoo is a colossal bellend. This travelling hippy (Andy Samberg) has spiritual psychobabble up the wazoo and hopes to loaf around his new family home while he writes a book. All but Ken and his son Dylan (Tyger Drew-Honey) are taken in by his cod philosophy, even his wife Lorna (Helen Baxendale); it's a pretty promising start.

British and American humour clash head-on in Robin French and Kieron Quirke's comedy which, on the evidence of the opener, manages to be both funny and annoying. When Rachel (Tamla Kari) arrives home from her gap year in Thailand, she surprises her doting, quirky parents, Ken and Lorna (the excellent Greg Davies and Helen Baxendale), by introducing them to her new husband, Cuckoo (American actor/comic Andy Samberg), claiming she told everyone about the wedding on Facebook. "I don't do Facebook, I'm 45," replies her dad. Cuckoo describes himself as "part teacher, part visionary, part firebrand". Needless to say, Ken isn't exactly enamoured with the goonish Cuckoo and wonders how her new man is going to support his impressionable daughter.

Helen Baxendale interview

Former Cold Feet star Helen Baxendale discusses her new BBC3 sitcom, Cuckoo.

After a successful pilot, Howard Overman's (Misfits) adaptation of Douglas Adams's detective tales gets a three-part run. Stephen Mangan stars as the gauche sleuth with a knack for solving cases by circuitous means. The opener finds Gently and put-upon associate MacDuff (Darren Boyd) in Cambridge tackling a conspiracy theory and a murder. Meanwhile, Macduff's girlfriend Susan (Helen Baxendale) is also in Cambridge at an interview for a new job which, if she got it, would mean the end of Gently and Macduff's detective partnership.

Helen Baxendale: I've been asked to do new Cold Feet

Cold Feet star Helen Baxendale has been asked to sign up for a new series of the hit drama - even though her character is dead.

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.

I like comedies, I like dramas. Comedy-dramas I've never been sure about and Dirk Gently has all but convinced me they don't work. The eponymous hero is a detective who believes in "the fundamental interconnectedness of all things" but after this outing, even he'd struggle to make a case for that hyphen straddling the two genres.

Gently is the creation of Douglas Adams who was working on another of his cases when he died. This one began with a missing cat and ended with what seemed like the attempted murder of the three attractive leads, Stephen Mangan as Gently, Helen Baxendale and Darren Boyd, who was in the recent Whites with Alan Davies and seems to be cornering the market in sidekicks to curly-headed fools. They all survived but surely the show won't.

The soundtrack twanged with Randall & Hopkirk-esque harpsichord (or did that pair use a spinet?).

The hero chugged around in a Leyland Princess. But Dirk Gently lacked drama, despite blowing all of BBC4's special-effects budget for 2011 on a warehouse explosion, and it lacked comedy with not one halfway funny line - this only making me yearn for the return of Mangan's cFree Agents from last year and scour Amazon for a cheap box-set of Baxendale's Cardiac Arrest, deadly certain laughs of the darkest hue.

There was something satisfyingly leisurely about Dirk Gently, adapted from a Douglas Adams novel about an old lady's missing cat, and starring Stephen Mangan as the one-man "holistic detective agency" hired to find it. It wasn't the smoothest of narratives. I could never wholly applaud a plot that so late in the day relied on hypnosis and time travel (the only sci-fi trace element from the original story). And, although there was laughter and invention, I'm not sure that bumping into a closed door aspires to the heights of modern comedy, even when accompanied by the ditsy loose-limbed rhythms of 1950s jazz. But it had a pleasing, meandering pace to it. You had to admire the way that Dirk's investigative method - based on "the fundamental interconnectedness of all things" - made an unlikely virtue of stringing together unlikely coincidences. And Mangan did a fine job as the eponymous oddball loafer-genius, with his boffiny corkscrew hair, love of biscuits and the rapid eye movements of a man accustomed to making a quick buck and a quicker exit; Darren Boyd was good, too, as the bewildered but biddable sidekick Macduff. As the girlfriend, Helen Baxendale was as nice as ever. It wasn't Sherlock, but I wouldn't mind seeing what a series could do.