The 28/2 'Cron ASPH is truly a magical lens, particularly on a film M.
This lens has become my mainstay lens. I have come to regard the 28mm as my normal lens and the 50mm focal length as a short telephoto, the same way some would think of the 75mm focal length.
If you have a 28mm and a 50mm, you have probably 90% or more of possible shooting situations covered in my experience. These two lenses would make an outstanding all around two lens kit.
@ Photon42:
I simply love your images in your post #33. Just outstanding! Congratulations on producing such great work!