Favourite Artwork

Although I mainly like Old Masters style of art, in particular the Arnolfini portrait by Van Eyck, I also like some of the more up to date paintings of such as Jack Vettriano and David Hockney. However, when visiting the National Gallery or similar, I am amused by people standing and staring for five or ten minutes at a time at a canvas with a few straight coloured lines on it, maybe in the hope that they will eventually come to a conclusion as to what the canvas is supposed to convey.