Tamron 28-75 F2.8 XR AF Lens

This lens is better than you would expect. Decent build quality certainly better than a nikon amateur zoom lens like the 18-70 or 18-55. Sharp in the center even at 2.8. I never used it on full frame. Produces images with excellent dreamy bokeh. I never shot it on full frame. For reasons I don't understand it does occasionally miss focus but good technique reduces this possibility. As far as I am concerned any nikon non AF-S lens has this problem anyway. Perfect focal length for for shooting people. You need this lens if you are shooting a wedding on a budget. There is no substitute for a 2.8 lens. Buy and sell it used it will cost you nothing. Supierior to the 18-200 in brightness and possibly sharpness at these lenghts.
Worst problem is nasty moustache distortion at wide end but this would not be used as a wide lens. Best feature is very decent macro performance and small size. Also I like the zoom lock feature for walking. I rate as excellent taking into account price and size. Nikon prime lenses are brighter and sharper in these focal lenghts but don't have macro or zoom. A nikon 2.8 17-55 or 24-70 are monsters in size and weight in comparison. Perfect walk around lens that does not stick out like pro 2.8 nikon. Oh yes it kind of needs a hood as it does flare quite easily. Don't even think of using stup up rings (67 to 77) as it will flare.
To give you an idea of my taste I think the 18-70 sucks. The 18-200 has unacceptable distortion. The 18-55 is not that sharp as rockwell says. The 17-55 2.8 is Awesome from 24-55. The 105 micro is perfect. The 50 1.8 is super sharp and does not ghost like the 1.4. The 12-24 sucks wider than 18 and the tokina 2.8 11-16 is incredible on a d300. The 70-300VR is the best amateur zoom nikon makes. www.robwouds.com