I think the best one, probably again at the Tate, was a pile of black rubbish sacks (that's trash to those over the pond). They had a problem because the bin men removed the exhibit, and yes they binned it. So the artist was called in to do it all again. Great art.

The greatest part of wisdom is learning to develop  the ineffable genius of extracting the "neither here nor there" out of any situation...."