Where you have a wide landscape it is sometimes nice to have a fisheye lens to capture the scene. However the lens you use will depend on weather you use a DX or FX full frame camera.
Nikon DX (APS-C) Lenses
With the Nikon 10.5mm f/2.8G Fisheye Lens Review we have the widest lens for the DX cameras. This lens covers 180 degrees and gives a full fisheye effect. In general the fisheye lens will create distortion of the scene but some photographers like this effect, there is plenty of software available which can correct the distortion in photoshop. This lens is considered as an excellent lens with very high image quality with some photographers consider even shaving off the built in lens shade and using the lens on full frame FX cameras, it can prove to be quite effective when used in this way. This fisheye lens has excellent image quality and is highly recommended.
There have been many many beautiful images taken with this fisheye lens. As an example of some beautiful images with this lens take a look at the Flickr site for images of the Nikon 10.5mm fisheye lens.
Nikon FX Lenses (Full frame)
The fisheye lens for full frame FX cameras is the Nikon 16mm f/2.8 Fisheye Lens. This lens is a much older design than the newer DX fisheye lens but it still provides a very useful wide, 180 degree view. Some of the subjects for a lens such as this would be landscapes and building interiors, if care is taken with the distortion or that the distortion is removed with software. Some spectacular sporting images have been taken with these fisheye lenses of subjects such as skate boarders and snow boarders and skiers.
If you are using a full frame Nikon FX camera then take a look at some of the images here of the Nikon 16mm Fisheye lens. This lens is highly recommended if you want a super wide angle view and excellent image quality.