Looking for an old portrait lens for Nikon

I would suggest the Nikon 100mm /2.8 E series lens. the lens is extremely good for the price point, although it's build quality is a bit sketchy. The plastic barrel wouldn't be my first suggestion for lens material, but if you treat the lens right it will last. I have owned my copy for well over 15 years now and it's still perfect. There are better portrait lenses, as suggested the 105mm is quite good, also the old 85mm/1.8 may be a better lens, but at the price point the 100mm E holds it's own. Odd but true.