The Weekend's Viewing: Kevin Eldon can make a dumb joke and a clever one simultaneously, a trick he pulled off more than once

It's Kevin, Sun, BBC2 // The Lady Vanishes, Sun, BBC1 // In the Flesh, Sun, BBC3

Comedies are both the easiest and the hardest kind of programmes to review. On the one hand, it's really simple to tell whether it's worked, since there's actually an audible signal to register the fact. As with pornography, success is registered by a bodily response rather than a cerebral one. But, as with pornography, it's intimately a matter of personal taste. You can no more rationalise a third party into laughing than you can argue them into becoming aroused. From the involuntary wheezing noises that persistently interrupted my viewing of It's Kevin, I can be absolutely sure that it's my type of funny. The problem is that anything I write about it is doomed to be an elaborate paraphrase of “I just liked it”. All I can hope to do is explain why.

Kevin Eldon himself is the obvious place to start, an enlivening spice in other people's sketch shows and comedies for years now, but here the headline act for the first time. And he can make you giggle just by looking at you, gifted with a face that can twist from bland normality to something gargoylish in an instant. For evidence, see the opening sketch, in which an aggressive drunk staggers down a hospital corridor, abusing the policeman and the nurse who are trying to guide him into a side room. When the camera closes in to look through the door, you see a surgical team ready to go and the same nurse vainly struggling to get the drunk into a surgeon's gown. It's a decent rug-pull, but Eldon's wild clowning gilds it.

Then there's the ingenuity of the structure, a ragbag of sketches and spoofs that pretends to be a free-form mess and is anything but. “Look, cards on the table... it's certainly not subtle or erudite...” said Eldon casually, introducing the format at the beginning. At which point, a giant boxing glove appeared from the side of the screen, whacked him into cartoonish grogginess for a couple of seconds before he snapped back to earnest sincerity “...but at least it's made by somebody who cares.” That's a dumb joke and a clever one simultaneously, a trick he pulled off more than once.

Best of all, it keeps you on your toes, jinking from relatively straightforward sketches (including a lovely sequence in which Eldon plays Adolf Hitler as the Beatles' producer George Martin, languidly recalling the day “me and the boys marched into Poland... and I immediately knew we were on to something big”) to more surreal self-reference. And it has the funniest and most engaging title sequence I've seen for a long time. And it even had a joke about pornography, when Eldon's secret stash is retrieved from the couch he's sitting on and turns out to consist of a publication called Mildly Flirtatious Ladies. What can I say? It really turned me on.

Diarmuid Lawrence decided to steer clear of a straight remake of Alfred Hitchcock's version of The Lady Vanishes, which was perhaps sensible. You don't take on the Master lightly. Unfortunately, he and his writer, Fione Seres, decided to go back to the original book by Ethel Lina White, which wasn't sensible at all. Bang go Charters and Caldicott, the cricket-loving pals who allowed Hitchcock to flirt between comedy and thrills. And in comes Tuppence Middleton as Iris, obliged for some reason to play the heroine as a petulant little trust-fund type, so self-entitled you really don't care whether she triumphs over the baddies or not. Hitchcock made the case for a silly thriller by plugging it into the profound anxieties of Munich and simultaneously pushing his tongue into his cheek. This new version sadly makes no case for it at all.

In the Flesh does for zombies what True Blood did for vampires, presenting them as victims of social prejudice rather than monsters. It's got heart and brains, and not all of them are splattered over a supermarket floor.

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