I have had a Nikon D70s for around 4 years, my go to lens is my Sigma 50-500mm, also known as the Bigma
. Its a pretty versatile lens, although not the fastest, its still a good value in my book. I toy with the idea now and then about getting a D300, but really don't use the camera as much as I would like or warrant the cost, but hey, since when does that matter.