The Alte Pinakothek, of Munich, Germany, has graced us not only with many works on its website, but with images of remarkable quality. Two that I recommend especially are --
Adoration of the Magi, Columba Altarpiece, ca. 1455, by Rogier van der Weyden Virgin and Child with Sts John the Evangelist, John the Baptist, Michael the Archangel and Dominic; ca. 1494, by Domenico Ghirlandaio.
Click on each image, and prepare to be impressed!