I always kept mine in their original packaging and stored them in drawers or lately these tiered type organizers that I found in a thrift shop.
Now I am in the process of putting them all in DVD type containers that are lined with magnetic sheets. It is kind of an expensive conversion..and I plan to put them on a shelf.
My friend told me that she is going to store hers on a magnetic white board from Hobby Lobby. That might be a neat way to store them if you don't have a lot of space and would imagine that it is reasonable if you purchase the white board with a 40% off coupon.
Have an awesome day!