Popular Photography ranked the Contax 50/1.4 as the sharpest, followed closely by the Canon EF 50/1.4. That was for SLR lenses and that was some years ago. That was also Popular Photography so take it for what it was worth. I don't remember the date but I had the issue until a couple of years ago when I cleaned house.
My opinion: the best normal lens is the normal lens that fits the camera you like to use at the time.