Contax Planar 50mm f1.7

     Zeiss developed the planar design.  It is the standard for all 50mm lenses produced today and for good reason.  Combine a great design with great glass and great coatings and you have the Contax Planar 50mm.  Essentially, this lens is as good as it gets without spending $1000.  You may notice minor fringing when using this lens on a digital body in harsh lighting, but is easily correctable.  

planar lens review
planar lens review