I was lucky enough about 6 months ago to receive a lens that really is the most amazing lens I have had a chance to shoot with.  This of course is the Nikon 85mm f.14G.  This lens is incredibly sharp and is able to throw the background so smoothly out of focus to create magical photos.   Able to shoot in dim lit areas as well as be super sharp even at f1.4 it is just an all around amazing lens. 

I don’t do the technical tests, you want to read that go here: http://www.kenrockwell.com/nikon/85mm-f14-afs.htm

Here is a shot I took yesterday just messing around, had the lens on my D700, sb-700 (-1.0) on top just to give a catch little light in the eyes:


Just stunning how well it at f1.4 it keeps the face sharp and the background so smooth.   The AF speed is good, not the fastest but this is to ensure good focus at f1.4.  it will auto focus on even the D3000, D3100 and cameras without auto focus.  Manual override for when the situation arises is just grab the focus ring, which comes in handy more than you think.  

This is a must have for someone into serious portraiture and professional photography.  Just the use in dim light pays for itself.  It is just a fun lens to use.