I was so incredibly impressed by the site specific installation by Anish Kapoor in Deutsche Guggenheim in Berlin called Memory. It took me a while to think about it and this again and again and this is usually a clear signal to me that an artwork somehow works for me.
First I loved tha way the title tells everything about the work: you will never get to see the entire piece, you only can use your memory to somehow put it back all together.
Second, I loved that for once I payed the ticked NOT to enter the museum. I loved to look at the texture of the surface of the piece, I love the total black in it and the silence you could hear standing in front of it (it's such a pity they decided to place the window to look in it right beside the bar but anyway...)
I loved it so much that when I heard people (yes, they were italian) complaining because they payed 3€ to see it I was almost going to shout at them. :)