Banksy has become famous for being famous, which is quite an achievement considering we are not certain who he is. Like all famous artists, he is often reduced to a cash value – making his artworks as nickable as they are memetic. The animals Banksy has been painting in unlikely London sites this summer are causing a now-familiar surge of adulation and hubbub. Yet behind his (anti)celebrity cult, Banksy is an artist whose work veers wildly in quality. At his best he’s a satirical agent provocateur with few rivals. At worst he’s vacantly sentimental or ideologically crass, often both at the same time. So which Banksys are worth making a fuss over and which deserve to be left in a skip?