[Arkady]

Right - 'budget' prime lenses from the major players will always be better than even their own zooms in the same range. And if you buy a 'slower' prime, it'll be even better optically, as typically the compromises made to increase max aperture speed tend to affect image quality. Not by much, but noticable under test conditions.

My best lens is an old Summicron-M 35mm f/2 which is still mounted onto my Leica M6. Leitz optics are the DBs - they set the standards by which many others are judged - the 50mm f/2 Leitz optic was, I think the sharpest lens ever tested by AP and may still be for all I know.