Nikkor is the brand of lenses produced by Nikon, the name comes from the older Westernised name Nikko, which means ‘sunlight’ and is the name of a town, north from Tokyo. If you are even near nikko you should visit that place, it stunning.
I primarily use prime lenses because of the quality and light sensitivity. My favorit is the 50mm f1.4 AF-D, is has a tremendous aperture. It's one of the sharpest and fastest lenses made by Nikon for a very good price.
Nearly all lenses made by Nikon from 1958 fit on my analogue cameras although I prefer AF and AF-D lenses. The Nikon G-lenses have no aperture dial to set the aperture manually. So that does not really work for me as my cameras are not fully automatic.
Back in the days I use to own some Sigma and Tamron lenses as well. These were not of the best quality back then so I had to let them go. Nowadays the quality seems to be much better I've hear although I don't own any at this time.
Spending money on glass is more important the spending money on cameras. The quality of your picture first comes from the photographer, then the glass, then the camera. Film is somewhere in between. Photography is an art, Cameras and lenses are the tools
Primes have my preference not just because of the quality of the glass and the speed but also the way you take pictures with a prime lens. If the composition is not right you have to move. The perspective will stay the same in contrast of a zoom lens. When you get used to shooting prime you know what the composition will be before you put the camera to your eye because you get to know your lens after a while.