What is the sharpest lens you own?

hotdog321 wrote:

Just for fun, what is/are the sharpest lens(es) you own? What lens performs best in overall terms of sharpness, chromatic aberration, distortion, contrast? What lens makes just gives you that "wow" feeling when you see the photos?

I'll kick it off with my old 300 f/2.8 (non-IS), a 100 f/2.8 macro (the non-IS version) and my trusty 70-200 f/2.8 IS (version 1).