The Rarest Porsches; at least what puts them on a list.

We would like you to state in your experience the rarest Porsche you have ever seen.    What rare cars have you seen in your town or city?   Have you seen a unique setup or any kind of hard to find models, even some that might be for sale?  What is it that particularly helps you distinguish interesting aspects of your 911, 914 or 944?     Do you have a museum in your town that has any Porsche road or race cars in them?