Kunsthistorisches Museum is one of the oldiest museums of the fine arts and decorative arts in the world and it houses one of the most important art collections in the world - known is mainly the Bruegel picture collection. Also masterpieces by Caravaggio, Lucas Cranach, Anton van  Dyck,  Il Guernico,  Dürer, Giorgione, Hans Holbein, Raffael, Rembrandt, Guido Reni, Rubens, Tiepolo, Tintoretto, Titian, Velasquez, Veronese, Fetti, Vermeer van Delf, Canaletto, Correggio etc you can see here.