In the past few years, we have covered plenty of amazing Novascopes here. This 16-Inch Star Matrix Novascope is one of the coolest ones we have seen though. It is a large geodesic spheroscope from David Sugich that produces trippy imagery. You can use it with flashlights and UV lights to experiment.
You can find these kaleidoscopes on Novascopes.com. More info is available here.