I always think there is nothing like the real thing.
As we stood in front of the original Leonardo da Vinci cartoon of The Virgin and Child with St Anne and St John the Baptist in the National Gallery I read that in 1501 crowds gathered in Florence to view it. The knowledge that today crowds gather in London to look at it thrills me - and that in relation to this drawing i am standing where Leonardo stood.
Other originals, other thrills - the Matisse collages in Tate Modern, Daniel Barenboim playing there on the stage in front of me in the Usher Hall in Edinburgh, chinese artist Fu Wua creating a brush painting with such energy and panache as I stood beside him, discovering a neolithic axe head on an archaeological dig in Cyprus...
Facsimiles are disturbing. The intention of the maker is very different from the intention of the original creator of the David in Florence or the Four Horses of the Apocalypse in St Mark's Square in Venice. I believe the quality of the intention of the maker becomes the spirit of the artwork. (My theory is that that is why we are drawn to children's art - their intention is so pure.)
Holograms are disappointing. The culmination of the Yorvik exhibition in York was supposed to be the Viking helmet found on the site. In it's place was a hologram. I can still remember my dismay.
Of course experiencing the real thing is not just about famous or cultural things....