David Walliams replaced by Bruno Tonioli as Britain's Got Talent judge

David Walliams has been replaced by former Strictly Come Dancing judge Bruno Tonioli on the judging panel for the new series of Britain's Got Talent.

Murder in Successville is ridiculous. Each week it takes a real-life celebrity, and places them in the middle of a fictional murder mystery, which they must help to solve. Successville, where these crimes take place, is populated by celebrities doing ordinary jobs, only these "celebrities" are impressionists doing their versions of those celebrities doing ordinary jobs. It's part sketch show, part structured reality show and part quiz show. Its jokes are largely crude and scatological. Everyone is on the verge of laughter throughout.

In the opening episode, the celebrity stooge is Jamie Laing from Made in Chelsea. I've never seen Made in Chelsea, so he well could have been the impressionist's version of Jamie Laing, though a passing colleague saw him on my screen, confirmed it was the real Jamie Laing and declared him to be "the worst". Laing plays a rookie cop tasked with cracking the murder of Strictly Come Dancing judge Bruno Tonioli, who, in Successville, is a chef married to chief suspect Darcy Bussell. Neither are played by themselves. Local gangsters Alan Carr and Harry Styles are not themselves, either. Nor, disappointingly, is ballistics expert Taylor Swift actually played by Taylor Swift.

This is a very, very silly show. For the first half I was torn between feeling extremely pleased something so anarchic and daft had been commissioned by the BBC in the first place, and willing it to be just that little bit funnier, and less reliant on jokes about bumming. But eventually, it got me. Laing gamely plays along as he is directed towards increasingly absurd situations, such as interrogating Alan Carr's underworld "sister" Jimmy Carr, who communicates only in that seal-bark laugh.

If Laing really is a villain in Made in Chelsea, then Murder in Successville is a remarkable act of rehabilitation for him. He just can't stop giggling, and it's helplessly contagious. This is the same silly joy that comes from sitcom blooper reels, or performers corpsing during live comedy, or trying not to laugh when you're getting told off. It's not particularly sophisticated, but it is surprisingly charming, and perhaps some of those remaining BBC Three-on-TV viewers might have stumbled across it and been charmed by it, too.

Radio Times review

This is silly. Very silly indeed. Successville is a town populated by celebrities - Gordon Ramsay's the chief of police; Mary Berry runs the strip joint - and policed by maverick DI Sleet. All these people are played by actors (Tom Davis is hilarious as Sleet). But when restaurateur Bruno Tonioli is found dead, Sleet is partnered with a celebrity rookie, Made in Chelsea's Jamie Laing, who's parachuted in to help solve the case.

It's a mixed-up structured reality comedy cop drama impressions show. Yet it boils down to a bunch of comedians saying increasingly ridiculous things to make Laing corpse, which he does a lot. Brilliantly silly.

Radio Times review

When Would I Lie to You? takes off, there's nothing like it. You get to a point where everyone in the studio is having such a high old time ribbing each other, they've almost forgotten they're on a panel show - and there are a few of those in this cracker of a show.

Bruno Tonioli is trying to convince us (and David Mitchell) that he once caused a fire while making pasta for Bananarama, whereupon Rob Brydon runs with it and does an impression of Bruno choreographing Bananarama that stops the show for a while. Then when Bruno tries to mock Mitchell's long-winded style, the comeback is pure joy.

Elsewhere, Adam Buxton maintains he has arguments with his partner via Skype and Kirsty Wark recalls a tiff with Jeremy Paxman over his Snoopy mug.

The gloves are off as a trio of talent show presenters go head-to-head-to-head. Bake Off's Sue Perkins turns up the heat as she tries to convince Frank Skinner mime artists should be silenced once and for all - and will Hair's raven-maned Steve Jones and Strictly's alarmingly décolleté Bruno Tonioli be able to conjure up pet hates to counter her case? Flat-pack furniture and gym etiquette are among the subjects nominated for eternal damnation.

Radio Times review

Radio Times still has in its trophy cabinet a golden bowling pin that our crack team won in Frank Skinner's press invitational bowling tournament some years ago (narrowly beating The One Show). So it's no surprise that the host isn't sympathetic when Sue Perkins suggests consigning one of his favourite sports to Room 101. Instead, he upstages it with a clip of "cat laser bowling", a heartless pastime that cat lovers should on no account watch.

Perkins is on good form, though. She describes a mime artist as "a clown you can't hear coming" and mail-order clothing catalogues as "40 pages of wan nymphets in clogs". Also on the panel are Steve Jones and, showing a ridiculous amount of chest, Bruno Tonioli.

All the stars are out - Dev from Coronation Street, one of the Nolans, an actor who used to be in The Bill - and they're up and dancing as Manilow runs through those peerless greatest hits. Go on, scoff if you must, but Manilow has produced some belters: Mandy, I Write the Songs, Can't Smile without You and camp classic Copacabana.

If you can get through the cheesy links (he loves his British fans and he's got a new album out, of course) and put up with Strictly's Bruno Tonioli making it all about him, then this is an unbeatable way to end the week. All together now: "Her name was Lola, she was a showgirl..."

It's a fate you wouldn't wish on your own worst enemy: Bruce Forsyth must have done something very bad in a former life to have his recent gruesome grilling by Piers Morgan, a man who insists on probing where no one wants to go, swiftly followed by the undercooked fawn-fest that was Bruce Forsyth: A Comedy Roast.

Starting with the dreaded words 'please welcome your host... Jimmy Carr!', a phrase guaranteed to have me instantly gagging (but not in a good way), C4's resident Smug MC, a ventriloquist's doll in human form, launched into his unique brand of makes-you-want-to-slap-him charm. 'A roast is like good-natured bullying,' he smirked. 'Good-natured in that it's happening to someone else, not you.' Unbelievably it was downhill from there, a gruesome selection of backslapping/stabbing blokes taking turns to out un-funny each other. Jonathan Ross started off with his tired effing and blinding routine, clearly miffed he wasn't talking about his favourite subject (himself). No, he was there to dishonour Bruczie, so what did Ross's rapier-like wit conjure up? No idea, it was instantly forgettable, other than setting up the night's weary theme: wow, Bruce Forsyth is, like, really old. He's done lots of dodgy gameshows. And he's got a chin. And a beautiful wife. Satire it wasn't.

Jimmy Hill's chin twin guffawed through gritted teeth throughout, taking it on the proverbial. But his lizard-like stare needed double-glazing to get through the kill-the-room combo of Bruno Tonioli and Arlene Phillips, whose contribution was up there with such classic double acts as Sam Fox and Mick Fleetwood and Rula Lenska and George Galloway for making you want to stab your eyes out.

All this crackling-free, toothless 'roast' proved was that the more people ho think they are funny there are in a room, the less likely you are to have a laugh. Only Sean Lock emerged with dignity intact but his best line - a dig about being surprised that Ross turned up in person instead of persecuting a national treasure by phone - was all over the trailers, so you'd heard it anyway. Next up it's Sharon Osbourne then Chris Tarrant - truly, C4, you are spoiling us.

Although it might not sound it, a roast is the ultimate honour for any entertainer. First started at the New York Friars' Club in the 1920s and made famous by Dean Martin on his TV show in the 1960s and 1970s, a roast involves you sitting in a room with your friends, family and colleagues as they mercilessly take the mickey out of you - goodnatured bullying, as the host Jimmy Carr calls it. There are three roasts this week - don't miss Sharon Osbourne's on Thursday and Chris Tarrant on Friday - but first up is Mr Showbusiness himself, Bruce Forsyth. Lining up to pay mocking tribute are Jack Dee, Jason Manford, Bruno Tonioli, Arlene Phillips, Jon Culshaw, Barry Cryer and, best of all, Jonathan Ross. It may be sycophantic, but there are still some hilarious moments.