I would suggest going to a photography specific site and ask this question. Who makes the best lens for a particular application is a loaded question. All the manufacturers mentioned, Nikor, Sigma, Tamron, Cannon, etc. all make some great lenses, but at the same time at certian price points, speeds, and mm some are better than others. I have a Tamron wide angle zoom that I use with my Nikon N70, 95% of the time. After doing my research when I bought the lense I determined for the amount of money I wanted to spend it was best lense for my needs. Was there a better lense? Yes, Nikor made a faster lense with probably slightly better optics, however, it cost over 3x more than my Tamron. For the manner I use the camera it didn't make sense at the time. Also don't rule out a quality used lense. Do your research and check out a local high end camera shop.