After numerous failed attempts to go to Berlin’s Hamburger Banhof in the past I committed and stuck the queue out late on a particularly nippy Sunday afternoon. But why only two ticket desks? Really, are you that inflexible you can’t add more? Perhaps online booking? You aren’t a little backstreet gallery – you are the Hamburger, you’re not even a Kebab! Anyway, the wait in North Face conditions was rewarded with not ein, not zwei but drei supreme exhibitions: a wonderfully endless Martin Kippenberger retrospective, spooky 2d/3d pieces by Martin Honert and an unveiling of the extraordinary mind of George Widener. Numerical genius – check him out. Honert is now over but the other two will remain open through the summer.