I am not a nikonian so personally I have never used Nikon lenses, but you can visit the nikon page below and check out their listings: (also check sample images for each lens so you can get some idea of its range)
Nikon | Imaging Products | Micro
I would suggest “AF-S VR Micro-Nikkor 105mm f/2.8G IF-ED”
check out its pool here:
Flickr: da100fotos’ stuff tagged with afsvrmicronikkor105mmf28gifed
But like I said browse those lenses, and check out the sample pools and the pics uploaded on flickR by ppl using those lenses.
Saath mai price compare bhi kar lena, aur jonsa acha lagay lay lena, according to ur budget.