Lucy Mangan

Gavin & Stacey (BBC1) are back for a third and, we are told, final series. But we won't dwell on that because the thought of television schedules bereft of this last tiny bastion of warmth, wit and occasional tiny oubliettes full of wisdom is one I cannot hold for long without tears starting to brim.

It is Gavin's first day at his new job, now that he and Stacey have moved back to Barry. He is trying to present a professional front to his boss while fielding the vast array of phone calls, presents and sandwiches that are the unsought side-effects of close family relations.

I still can't see how anyone can be even tangentially involved with, never mind married to, Stacey without large doses of drugs and/or therapy, but Nessa continues to draw the sting of her presence with her own magnificently disaffected progress through life. She has strapped baby Neil to her back so that he no longer impedes her smoking. She has delegated all the cooking for his christening to Gwen, and is planning to spend the remainder of the £6,000 Doris lent her on vaginal rejuvenation. Oh, and the christening do is doubling as an engagement party for her and Dave: a discovery that naturally pains Neil's dad, Smithy, and not just because he stumped up 400 quid for costs before she told him. Is there a flicker of yearning behind Nessa's eyes as Smithy takes the baby for a photo, portending a happy ending for these two kebab-crossed lovers? Or has she just realised that she's left a packet of fags in his nappy?

In the closing scenes, Stacey and Gavin decide that they will start trying for a baby. I wouldn't trust Stacey with an uncapped Biro myself, but who listens to me?

Cast Offs is a new comedy-drama from Channel 4 about a fictional reality show about six disabled people (played by actors who share their characters' disabilities), voluntarily marooned on a British island. Each episode focuses on a different character, their backstory alternating with scenes from their stranded present; last night belonged to wheelchair-bound Dan, beautifully played by Peter Mitchell. The show-within-a-show conceit so far seems unnecessary: just as the flashback narrative is drawing us in (last night's was full of tough and tender details of life as a newly disabled man), everything stops for stilted banter on the island. Unless this is intended to do something as crass as prove that disabled people can be as dislikable as any non-disabled reality show contestants, it seems pointless. Maybe this strand will reach the standard set by the other element soon - the second episode is tonight, so we shall see.

I am having to watch Psychoville (BBC2) from behind the sofa, lest the equivalent of The League of Gentlemen's Papa Lazarou (the mere thought of whom is enough to have me weeping with fear) emerges. But it is corking stuff. Robert the dwarf has turned out to be telekinetic. Joy is feeding her baby on blood and punching anyone who dares to suggest that the infant strapped to her chest is in fact a doll, while the serial killer-obsessed David "I like strangles" Sowerbutts and his mother Maureen are about to fulfil what one can only assume is a lifelong dream by murdering someone. That's if they can agree on a method. "I like drills." "You're not doing that, I've got a thumping headache."

So far, I am managing to cope with both the one-handed, embittered clown Mr Jelly and the eyeless (not just blind, but eyeless, very, very eyeless) toy collector Mr Lomax, who has taken on Tea Leaf as an employee (contractual terms: "No girls, no smoking and no meat pies") to help him track down on eBay the one Beanie missing from his collection. I am rapidly approaching the limits of my endurance, yet fear we are nowhere near exhausting writers Reece Shearsmith and Steve Pemberton's appalling imaginations. I suspect that when the mysterious blackmailer who is stalking them is finally revealed, none of us will ever sleep soundly again.

Ladies of Letters, the second part of whose 10-part adaptation from the radio show of the same name was shown last night, starred Anne Reid and Maureen Lipman as the letter-writing widows who keep their spirits up with sherry, shared recipes and long-distance one-upmanship. As with the radio version, the material is slightly thin, but you could watch (or in Prunella Scales and Patricia Routledge's case, listen to) the actors involved all day. Clever, that.

When I was at primary school, we once did an almost-scientific experiment on a ready-made chicken kiev. You drop the chicken kiev in a Pyrex bowl full of water and time how long it takes for the thing to disintegrate, revealing itself not as a plump, succulent breast but the compressed shreds of gristle and meat from less mentionable poultry-places.

Last night the BBC served up the first episode of Mutual Friends, a comedy-drama about six old friends reunited at the funeral of Carl, one of their number.

It is, then, Thirtysomething meets Cold Feet meets Mistresses meets a little bit of The Big Chill meets innumerable other comedy dramas whose names escape me because my memory is too full of random pre-pubescent reminiscences to have retained anything new since about 1991.

It looks good and slips down easily enough, thanks to good performances all round, and particularly sterling work by Marc Warren - evoking another of life's unarmed and furious losers - but a moment's thought reveals it to be another artfully moulded mound of mechanically recovered meat from the carcasses of other programmes.

Buried amid the kind of stuff that would barely have passed muster in the 70s (does Dr Beenyman's pink coat make him look gay? No - his hair does! How has daft Cara managed to get through life without a piano falling on her head? I haven't!) are signs of both comedy and intelligence, but when all the jokes are spatchcocked into a wafer-thin plot that veers uncertainly between reality and surreality, this particular experiment can only be deemed a failure.

Scallywagga is that rare beast - a new sketch show that is more hit than miss, harnessing the power of the running gag almost as well as The Fast Show.

The cast look about 12, so if you'd rather be uplifted than made to despair of humanity by young people, I would suggest a restorative draught of the scallies now and again.

Why has the Summer Wine lasted?

How has a series about tin-bath surfing Yorkshire pensioners become the world's longest-running sitcom?

Knitted hymn book, Vicar?

Girls do have a good time when they get together, don't they? Particularly when the girls in question are a group of comic actors gathered round a Jennifer Saunders script like wasps round a pot of the titular breakfast spread in Jam & Jerusalem.