Painting is an ancient medium and even with the introduction of photography, film and digital technology, it still has remained a persistent mode of expression. So many paintings have been limned over dozens of millennia that only a relatively small percentage of them could be construed as "timeless classics" that have become familiar to the public—and not coincidentally produced by some of the most famous artists of all time. We, of course, have our opinion of what makes the grade and we present them here in our list of the best paintings of all time.