I am a Nikon user by preference but also us a Fuji S5900 for "quiet" work with Badgers as the fake shutter sound can be turned off.

Most of the pictures to date were taken with a Nikon D100 with a 70-300 zoom, with realy good macro.

I have now upgraded to a Nikon D300 with the following Lenses;
Nikon 18-70mm zoom, a really nice lens for landscapes
Sigma 180mm Macro, outstanding for butterflies, dragonflies and spiders.
Sigma 50-500mm zoom for birds, deer etc.

I also use a sigma teleconverter, which is really good when used on the macro lens, and a Nikon SB29s Ring-flash.