Armstrong & Miller

The two jovial comedians continue their quest to be the new kings of sketch comedy with the fourth instalment in this series. Tonight's highlight is "Divorced Dad" insensitively telling his young son that the reason the girl his son likes hasn't replied to his text message is because she's "out of his league".

While not every sketch is a side-splitter, those that do make you laugh out loud tend to creep up behind you and catch you unawares. Take this week's "Origins". It starts slowly with a group of grunting cavemen cooking a mammoth and then suddenly spirals into some very cleverly observed silliness ridiculing dinner-party small talk. It's brilliant. The Victorian pianist sketch - in which Armstrong keeps breaking into inappropriate and raunchy pop songs that offend his genteel audience - is another sneaky one. Culture buff Dennis Lincoln-Park has another accident with an "absolutely priceless" relic. The fact that you know what's coming makes it even funnier. The Second World War pilots don't want to dig out of a PoW camp because "We can't do escaping, isn't it? Because I've got all my asthma and s*** and he's got issues round worms." And viewers called Fred or Mick might like to know that they get a special mention this week when Miller's character Tom does his stream of "variations on a name" routine.

It's gentle, it's cosy, it's very British, and above all, it's a sketch show that's funny. Hurrah for Armstrong and Miller!

Like musical jokes. Never, ever funny, agreed? And yet, the best sketch in The Armstrong and Miller Show (BBC1) is the one where Armstrong is tinkling away on the piano in an Edwardian drawing room. Then he suddenly and seamlessly segues from Vivaldi or whatever into Gay Bar by Electric Six. Which makes the ladies faint. Funny, eh? Comedy, it's a mystery. Or possibly just pot luck.

I can't shake off the sense that this show has switched onto cruise control. It's still funny and there are excellent moments, but they come as occasional flashes. There isn't the sense of one belter of a sketch following another. Focusing on the positives, this week we get an inspired 1960s-style safety film that offers a neat solution to the lack of seatbelts in the backs of cars. And there's a new character, too: champagne-quaffing royal correspondent Terry Devlin, who sits in a breakfast news studio with a sweater draped over his shoulders answering questions such as "What would be the prince's state of mind at this time?" with an expertise that turns out to be distinctly limited. Alexander Armstrong's posh/slightly camp Northern Irish accent (if I'm hearing it right) for the character is a tour de force. Elsewhere, the Spitfire pilots have discovered that there's a spy in the ranks ("The group captain's well vex"). And the businessman who strides through the office taking on-the-hoof briefings learns "Beetroot's making a comeback" and "Nobody misses Sodastream". Plus, look out for a cameo from Dermot Murnaghan.

Chalkie Von Schmidt? A spy?! Theres some awfully bad news for the RAF pilots this week in another bunch of very likeable sketches from Ben Miller and Alexander Armstrong. A great old running gag makes a welcome return and a new character is introduced.

Its a royal correspondent who knows absolutely nothing about what the royals might be doing, eating or thinking but is nevertheless very happy to appear on rolling news channels and speculate about what he doesnt know at great length. It would be nice to see the pair introduce even more new characters like this one to keep things fresh.

Jilted Jim (the loser dumped on his wedding day for the DJ) pops up again tonight and the happy honeymooners probably arent the only ones groaning now every time they see his face.

Other bright spots include a warning about the danger of wearing T-shirts with writing on them. Meanwhile, the Neanderthals name a baby and we're reminded what a very dangerous decade the 1970s must have been by way of another terrifying Safety First film.

Consistently funny if essentially conventional, Armstrong and Miller's sketch show goes back to the old Kenny Everett format of using a handful of recurring characters to tell the jokes. Best this week are the prehistoric couple embarking on a naming ceremony for their newborn, who ends up being called "Mmm": 14 years later, Mmm is a classic grumpy teen forever frustrated when anyone bites into a tasty bit of mammoth.

Accident-prone art historian Dennis Lincoln-Park is in trouble again. Tonight, he introduces us to an "absolutely priceless" pen-and-ink drawing by Rembrandt. We know from the word go it's doomed, though it's still childishly funny when the inevitable happens. It's typical of Ben Miller that even when the scripts aren't classics, he lifts the material by his sheer comic energy. That's the case with his embittered solo honeymooner who tells anyone who'll listen about how his bride ran off with the DJ. Similarly, his car showroom customer who insists on acting out what might happen in the vehicle if he bought it ends up a surreal tour de force. Elsewhere, there are enjoyable spoofs on The Krypton Factor and the Olympic logo design, and Alexander Armstrong's RAF pilot has had a letter that makes him depressed: "Like with issues around self-esteem issues, you know?"

If Peep Show is the spirit of Channel 4, then Armstrong and Miller are BBC to the bone - harking back to the very dawn of broadcasting with their vaudeville performers, Second World War pilots and public service safety films.

But they bring them bang up to date by adding sex, swearing, violence and extremely bad wigs. One of their new characters this series is a respectable TV historian, named after an American rock band, and Dennis Lincoln-Park is back tonight to destroy another priceless artefact.

There's an enjoyable running gag about a very surprising new game show that's based on the Krypton Factor plus a welcome return for the overly truthful dad.

John Cleese once said that it was harder to be funny than to be clever. The Cambridge-educated Alexander Armstrong and Ben Miller obviously decided to take the high road and go for funny in the second series of The Armstrong and Miller Show.

Their sketches have no point or satirical edge to them. Teachers doing acrobatics while their pupils' backs are turned during an exam, an accident-prone art presenter, even their famous street-talking RAF men have nothing to say. Yet most of the stuff - barring a terrible Star Trek sketch that could have come out of Morecambe and Wise - works. The Blue Peter presenters apologising in child-speak for their off-air decadences may even turn into a classic.

The performances are meticulous. Particularly to be savoured on Friday was Armstrong's tactical use of accents: the northern Blue Peter man's pronunciation of "film" with an extra couple of Ls in it, and the info-commercial guy's voice suddenly dropping a few social classes when it came to saying "three tharsand peounds". There is cleverness here, but it is in the detail.