But is it art? The question is posed by the dirty old sleeping bag dumped in the entrance to the latest incarnation of the Saatchi Gallery in the old GLC building on the south bank of the Thames. At once the art virgin is thrown into disarray: should one ignore this smelly object or stop for a moment, consider its meaning and then move on and pay the eight quid? The presence of two rather burly security guards gives the game away. Yes! It’s art! We can feel enriched – and we haven’t even set foot in the gallery proper yet. How marvellous…

Billed as a Damien Hirst retrospective, the exhibition at London’s County Hall is nothing less than a greatest hits of Young British Art. Hirst may be the headliner but there’s a hell of a support bill, including Tracey Emin, Marc Quinn, Ron Mueck and the Turner-nominated Chapman brothers, the work all taken from the personal collection of Charles Saatchi – a man who buys art like the rest of us might buy CDs. There can be no doubt that it is an impressive collection, taking in everything from Emin’s bed to Hirst’s dismembered animals and all points in between.

But is it art? Well yes, but maybe not as we know it. For those only used to seeing great works behind glass from beyond a rope, it is quite a shock to nearly trip over Ron Mueck’s Dead Dad sculpture, lying unguarded in the middle of the gallery floor. And to find yourself standing at the side of that bed, alone except for yet another security guard, is a strangely disconcerting experience. After all the hype, headlines, shock and indignation, it really is just a bed. Glad to have seen it and all that, but the world didn’t exactly stop spinning.

Although the exhibition gives all comers a chance to make up their own minds about some of the most famous works in modern art, many exhibits are accompanied by the kind of pretentious hyperbole that can only complement such titles as Some Comfort Gained From The Acceptance Of The Inherent Lies In Everything (two dissected cattle). So, that isn’t just a bunch of dead fish in a case, it’s a bold statement on the futility of the human struggle. Or something.

The major Hirst pieces are a major case in point. They certainly shock and – in the case of the decomposing cow’s head of A Thousand Years’ – can make you feel physically ill, but is there much beyond that?

Unless it’s the always nagging sense that there is a real smugness about Hirst, particularly in his establishment-bating spin paintings, inspired by a feature on Blue Peter and currently selling for up to £70,000. There’s a joke being played somewhere and you can’t help but feel that it’s on us, or more accurately on those who lap this stuff up and pay stupid amounts of money for it. Which kind of includes Saatchi himself.

Buried amongst all this blood and guts are, however, moments where it all starts to make sense – mostly from artists who have yet to inspire the tabloid headline writers. Marc Quinn’s Self (a cast of the artist’s head filled with eight pints of his own frozen blood), Ron Mueck’s incredible sculpture and Richard Wilson’s 20:50 installation are all mesmerizing. Most striking of all is Marcus Harvey’s infamous portrait of Myra Hindley. Even taking into account that the children’s hand prints are in fact stencils, the painting is chilling, frightening and capable of moving you to tears. For me, it engages the intellect in the way that a thousand dead sheep, pigs or sharks never could. And it doesn’t need a small piece of card to tell you what to think.

Sure, there is a lot of shit around this whole Brit Art thing and it’s hard not to view the celeb fest that greeted the gallery’s opening with a degree of cynicism. You could equally argue that, in purchasing virtually every piece of work that emerges from the movement, Saatchi has created a sort of production line mentality that robs the artist of the need to struggle to be heard, and gives them nothing to kick against. Yet for all that, this is an exhibition worth seeing if you have even a passing interest in popular culture. It will either shatter or reinforce your preconceptions, engage or repel, provoke or disenchant. But, as I’m sure one of these people once said, any emotion is good emotion. And that might just mean that after all, this is art.