Tai-Shan Schierenberg is a painter of portraits, figures and landscapes. Famous for winning the 1989 NPG's John Play Portrait award, he now has been selected as a judge for a upcoming TV Arts talent show. Here he speaks of his current top 10 portraits at the National Portrait Gallery. Tai has a new exhibition 'That Obscure Object of Desire' on display at Flowers Cork Street Gallery Until 20 April