Wall Art care of the sun has to be my favourite.
Shadows pasted about the house each day, or at least on the days when the sun is out (which could add to the reasons I love them).
Altering from the amount of cloud cover, the time of the day, the time of the year and of course when I remember to clean the windows, mind you a bit of dirt and a few cobwebs does add a nice soft filter.
If you watch them they change by the second, different patterns and shapes appearing and disappearing before you could grab a camera (this one comes from personal experience).
We tend to take them for granted but once you start to look, you notice what a dominant feature they are around the house.
Add some reflections, some prisms from the glass and objects that the sun hits and you have a full on light show, sort of an in-house vivid.