Tamron AF 90mm f2.8 Di

D200; Tamron 90mm f2.8 @ f8 iso 400 ; 1/160

This lens is considered as legendary lens in Tamron Lens line up.
First produced as manual focus lens, and being redesign twice but still it maintain its well known optics quality.
Considered by Paul Harcourt Davies (professional macro photographer) as one of the sharpest lens available beside Nikon 60mm f2.8 and …..

Nikon D70s Tamron 90mm f2.8 ISO 200 f/9 1/320 exp +0.33 matrix metering

Look at the beetle...it is very sharp, even the hair in its leg revealed and sharp

It also provides very nice and creamy bokeh for portrait photographer.
In DX format, this lens becomes 135 mm lens which is popular range for portrait photography. It also produces almost no distortion which is ideal for portrait.
So besides being your macro lens, you could also use this lens as good portrait lens.
Compared to more expensive Nikon’s 105 mm f2.8, this lens could maintain only slight or even no difference in terms of image quality. And it outperforms Nikon 105 mm in terms of bokeh.

Nikon D200 Tamron 90mm f2.8 ISO 100 f/3.2 1/60 sec exp -0.6 matrix metering

don't look at the over exposed face...it's my fault, look at the bokeh behind it, very creamy and nice

Sharpness is flawless, like other macro lens performance…sharpness in close focus is excellent. But as you move closer, the maximum aperture change and become lower.
You shouldn’t bother about this since you will never use f2.8 aperture in close focus…it will result in very shallow DOF which is not applicable in taking photograph.

How about the color accuracy, saturation and contrast?
This lens produce superb contrast and saturation, but the color resulted often missed slightly compared to Nikon Lens. Well nothing is perfect…but it can be repaired anyway in post processing.
Now since Nikon 105mm lens have been redesign by adding VR capability, which increase it cost significantly…this lens become a very good option without any significant contender (for this focal length).