New Order - a Survey of British Art Today, Saatchi gallery: A unique best of British James Capper is as much an inventor as he is an artist, and that's always been something of a problem for him. Capper makes useless machines, like one resembling a giant yellow praying mantis that lurches and sputters over the ground, churning up earth with its gigantic claws. As you watch it in action, your concern is primarily for the safety of the driver perched high up in the teetering cabin - and for anyone unlucky enough to be standing in his way. Pretty much the last thing you think about is art or beauty. What is on display in this show is not one of Capper's machines but six lethal blades detached from it, arranged on the gallery floor. That may be because the machine wouldn't fit in the gallery, but the effect is one of sinister elegance. Next to it, a truly repellent object entitled Nipper (Long Reach) takes the form of a painted steel, electrically powered garden clipper enlarged to a size that could take a person's head off. By showing Capper's works in this way, Charles Saatchi hauls them firmly back into the realm of aesthetics, and specifically forces us to interrogate them as we would a Surrealist object. For the first time, I saw that Capper is creating the mutant offspring of the robotic creature who operates Jacob Epstein's Rock Drill - only Capper's monsters are moving, and they're headed straight for you. Capper and Balmforth both belong to a group of young artists who show with the Hannah Barry Gallery and are sometimes referred to as the Peckham School. I've made intermittent visits to the studios of Capper, Balmforth and Bobby Dowler (who is inexplicably not in this show), and attended poetry recitals by Nathan Cash Davidson. I don't know what I would have made of the strange, visionary art of Nathan Cash Davidson, had I not heard him declaiming from memory one of his surrealistic poems at Hannah Barry's gallery. Davidson is a child of the internet, who finds online the weirdly phantasmagorical images he uses in his pictures. He then processes those images through a vivid if chaotic imagination, recording what he sees in his mind's eye with a brush that ignores niceties such as perspective, composition, draughtsmanship and brushwork. His images of mythical heroes, witches, angels, and devils are disconcerting because the viewer is cut off from the thinking process that compelled Davidson to paint them. Though the selection on show here does not represent the artist at his best, it does give you some idea of the elusive appeal of his work. What is so striking for a critic who followed the careers of the YBAs is how earnest these Peckham artists are, how true to themselves. Their work isn't shocking or gimmicky, like that of their predecessors such as Tracey Emin. In some ways, they remind me of more low-key artists associated with the YBAs, such as Rachel Whiteread or Gary Hume, though they tend to use working methods that are closer in spirit to Constructivist and Surrealist practices of a much earlier date. I'm glad they are at last receiving recognition. I'm only sorry that Saatchi didn't push the boat out and do a whole show devoted to them. Moving away from the Peckham group, I love the delirious decorative whimsy of Charlie Billingham's pastiches of Regency wigs, breeches and bums all painted in the softest Rococo palette of pinks, blues and grey. I would also single out Spanish-born Greta Alfaro. Take the full 10 minutes to watch her two-channel video In Ictu Oculi ("In the Blink of an Eye") from start to finish. It starts with a still shot of a table set for a dinner party, groaning with food and wine, then you see the first vulture. Within seconds, scores of birds have descended on the feast, gorging and gouging until nothing is left. Then they disappear. Not exactly a new idea, but worth remembering nonetheless: life is a feast and it's over pretty fast. In general, the women in this show are a lot scarier than the men. Wendy Mayer's sculptures look as if they were made by Louise Bourgeois in a bad mood. She sews creepy little dolls with strange proportions and adult faces, and then arranges them in what should be harmless domestic scenes that don't feel harmless at all. Her best piece looks to me like a portrait of Bourgeois in the form of an oversize pincushion, into which Mayer has stuck giant pins, as though using voodoo to rid herself of an artistic presence that haunts her imagination. And the word "frightening" doesn't do justice to the power of Czech-born Tereza Zelenkova's black-and-white photos of the crocodiles which are used on a chicken farm back home as a cheap way to dispose of surplus birds, or the almost equally repellent image of a woman whose face is covered by hair so long it almost touches the floor. Not all of the art in New Order is this good, of course, but the show as a whole is 10 times more consistent than anything I've seen at the gallery since the underrated, if badly titled New Neurotic Realism in 2005. The catalogue essay and entries by Ben Street are first class and, best of all, Mr S hasn't made up a catchy umbrella of a title that implies that a bunch of artists whose great strength is their near-certifiable eccentricity have anything much to do with each other.