Take a look at this image made by Nikon and found by Petapixel, showing every camera the Japanese company has ever released. The history spans from 1948 with the Nikon I, though it only goes to 2008, which is a damn shame.
The poster would be a helluva lot bigger if it included the past five years of digital cameras. Nevertheless, it's a great image to spend a few minutes gazing at.
If you're really a Nikon fanatic, you can order it as a poster!