Foundation E. G. Bührle Collection

Assembled by industrialist Emil Georg Bührle, this Zurich foundation holds one of Europe's finest private collections. In February 2008, armed men walked in near closing time and seized four masterpieces by Cézanne, Degas, van Gogh, and Monet worth some $160 million. The Monet and van Gogh were recovered within days; the others took years to resurface.