There are innumerable discussions on Internet camera forums on the subject of which image format is best. As a primarily RAW-shooting photographer, I have strong opinions on that and will do my best not to be overbearing about it.
Yes, I am a NEF (RAW) photographer about 99% of the time. I think of a RAW image the way I thought of my slides and negatives a few years ago: this is my original file that must be saved and protected. The only problems I can think of for the RAW format are the following:
You must postprocess and convert every image you shoot into a TIFF or JPEG (or other viewable format).
There is no industry standard RAW image format, and Nikon can change the NEF (RAW) format ...