Either the Nikkor 50mm f/1.4G or the Micro 60mm f/2.8G is a good choice. The key benefit of the 50mm for portraits is the ability to throw the background way out of focus. However, wide open, that lens can also throw a subject's ears out of focus!
The 60mm G is plenty sharp wide open that eyes will look very good. However, your ability to throw the background out of focus at f/2.8 is somewhat limited. If you have an interest in closeup or macro photography, consider the 60mm, although it has less working distance than most people like on macro subjects (lighting and scaring the bugs are issues).
The Tamron macro 60mm f/2 would seem the lens that has the macro ability and is a portrait lens. This lens is clearly marketed toward someone with your needs. However, I would read the reviews carefully.
If your interest perhaps is more toward the closeup and macro work, consider the Micro Nikkor 85mm f/3.5. It's two-thirds of a stop slower max. aperture than the 60mm and a great lens for macro and closeups. It also has VR II.
A suggestion that nobody has yet made is to buy the Nikkor 50mm f/1.8, saving over $300, and to put that money toward trading your camera for a D90. These bodies are now available for about $750.
--
Adrian
