I'm new to photography and just starting to take photo in RAW format. I haven't found a difference in quality of color adjustment editing between ViewNX (free software coming with my Nikon d5100) and Picasa, perhaps because of my inattentiveness. So I've decided to ask here what is the best free software to get most from RAW (Nikon NEF) photo editing?
For the Mac, the best editor that will get the most (but is not exactly easy to use) is the Raw Photo Pro processor. It can do pretty much anything to maximize the raw potential. But if I may, I think that's going down the wrong path. You can get a little extra quality from processing the raw differently (I'm intentionally excluding post-raw conversion editing) but far more quality from how you setup the shot. Change in lighting, filters, angle, exposure, etc. can dramatically improve a picture more than subtle raw conversion improvements.
Even still, once a photo has been converted there is a world of changes you can do to an image that has far more ability to change perceived quality than what is done through raw conversion.