What I always liked about Nikon is that they were fearless when it came to odd cameras and specialty stuff.
One of the most monstrous creations they did was the High Speed F2H. It was designed for high speed of operation and just that. It had a fixed mirror, interchangeable screens and could shoot an insane 10 frames per second that is still quite high even by today's standard. It's even a high framerate when compared to modern DSLR's. It even came with an external battery pack for long says of shooting.
Since production was so low, it's now one of the most expensive Nikons on the market.