As the Turner Prize reaches its 25th year, art critic Waldemar Januszczak considers its transformation from a widely criticised award to a much anticipated and often controversial annual spectacle. Januszczak looks back at the art and artists that have grabbed the headlines and investigates how the Turner Prize has influenced the appreciation of modern art in Britain, with millions now visiting Tate Modern. The programme includes new interviews with Turner Prize-winner Damien Hirst, Tate director Nicholas Serota and art critics Matthew Collings and Sarah Kent.