We're almost at the end of this unique comedy creation, which serves up English countryside to the tune of top level bickering from Steve Coogan and Rob Brydon over a series of very expensive lunches.

Part of the fun is working out how much of their not very polite and utterly random dinner party conversations have been thought out in advance, and how much is just flowing off the top of their heads as the food gets shovelled in.

Tonight, in the Nidderdale Valley, they're riffing on an Abba song, the comparative merits of Les Dawson and Woody Allen, and they learn more about limestone than they could possibly ever want to. Yes, it's all very moreish.

There is no justice in the world, clearly. Otherwise, why would the dreadful sitcom How Not to Live Your Life be allowed to survive into its third series? More to the point why does its charmless star/writer/producer, Dan Clark, have almost total creative control, like he's Woody Allen or something?

He plays a feckless, gaffe-prone berk who constantly finds himself in sticky predicaments, usually in an effort to impress his attractive female housemate. This premise could probably provoke a few laughs in the hands of a more talented comedian, but Clark is terminally uninspired. The latest episode even featured a cameo from Noel Fielding, just to seal the comedy vacuum.

Lazy and obvious, the only fun it provides is in seeing how often you can predict each punchline.

It was a curate's egg of a half-hour, not that a curate and his egg offer the best metaphor for a show about a loving but bickering family of east London Jews. In fact, it is a singularly ill-fitting metaphor, the expression "curate's egg" originating in the old Punch cartoon about a curate who was too timid to complain about a bad egg he had been served. There would be no such timidity at any table of Jews worth their salt beef. Even a visiting rabbi would spit out such an egg.

Enough eggs already. Grandma's House revolves around the simple idea, one that dates back almost to the birth of television comedy, of different generations of the same family arguing in a front room. Steptoe and Son did it to great effect, so did Til Death Us Do Part, so did The Royle Family. In some ways, Grandma's House is The Royle Family with chopped liver. In other ways, it is Seinfeld removed to Gants Hill. And the nod to Seinfeld is evident in the character of Simon (Simon Amstell), the presenter of a TV comedy panel show about music, which - just as Jerry Seinfeld played a stand-up comedian called Jerry, a mildly fictionalised version of himself - is precisely what Amstell, the co-writer of Grandma's House with Dan Swimer and erstwhile presenter of Never Mind the Buzzcocks, is in real life. Or was. Indeed, in last night's opening episode Simon announced to his family his intention to quit his TV show, much to their dismay. "In my kalooki group that's all we talk about," lamented his grandma (Linda Bassett).

The other obvious parallel with Seinfeld is that Jerry Seinfeld made it through nine seasons of that phenomenally successful show rarely ever being more than engagingly wooden as an actor. Good acting was the preserve of his brilliant co-stars and so it is here. Amstell barely seems to try to act, just issues his lines semi-mechanically wearing a half-smile, just as Jerry did.

Still, it didn't matter in Seinfeld and, strangely, it doesn't matter here either. Amstell, aided by the sensible decision not to run a laughter-track, somehow makes a virtue of his self-consciousness, and in any case, there are enough pitch-perfect performances, notably from Rebecca Front playing Simon's divorced mother, Tanya, and Samantha Spiro as his aunt, Liz. It helps that the writing, too, is often pitch-perfect. Tanya is being courted by Clive (James Smith), whom Simon loathes, but who is considered highly eligible largely on account of a 42-inch plasma TV on which "you can see every hair of Noel Edmonds's beard". And when Simon's grandpa (Geoffrey Hutchings) breaks the news that he has cancer (an unwittingly poignant detail, given that Hutchings died suddenly last month), it is questioned on the basis that "years ago he found a lump on his testicle and it was a raisin in his pants".

Just as a wandering raisin can be mistaken for a testicular lump, so can a promising first episode be mistaken for a good new sitcom, and I wouldn't like to commit myself too soon. Besides, there are reasons why London-Jewish humour is far less familiar to us than the kind of New York-Jewish humour exemplified by Neil Simon, Woody Allen, Seinfeld and Larry David (whose Curb Your Enthusiasm also has loud echoes in Grandma's House). It is no accident that the Jewish humour British audiences know best and love most has historically been imported, mordant and razor-sharp, from the United States. Nor is it any accident that Jewish characters in British sitcoms are, for the most part, pretty forgettable. It is more than 40 years since Never Mind the Quality, Feel the Width, and not even the warm glow of nostalgia does it any favours.

In Pete Versus Life, the winner is Woody Allen

Channel 4's new sportswriter sitcom is decent enough. But its central joke has been done before - and better.