Digital BW, The Print

As posted back then, we downloaded and tested demos of all the major
noise/grain plugins about a year ago. 
Personlly, I thought the Noiseware filter was the best in terms of
image quality.
But Noise Ninja was a very close second, some people could not see the
difference, and had an interface that was easier and faster to learn
up front so we got it. They both beat out Neat Image, which was still
pretty good.
You can do as much bad as good with these filters...
Tyler