This is the latest and greatest, at least for Nikon.  Lens analysis is limited to handling in the field.  There are other web sites with comprehensive test results. 

24-120 Nikkor

200 F4 Micro Nikkor

500 F4 AFS-D

18 F4 Nikkor

There is some really good glass available that rivals that of the major brands.   While the independent lens manufactures typically cater to the price conscious, sometimes they develop some really interesting and advanced technology such as the Vivitar Series 1 line (1970's) and the current Sigma big glass with HSM.  

Vivitar 800 F8