When I started developing my own film in the late 60’s I used half a dozen different films, three or four developers, stop bath concentrate, fixer with separate hardener, rinse aid, and lots and lots of tap water. Today I use just five materials:
FP4 Plus and HP5 Plus Film – These traditional black & white films with their wide exposure latitude and long gray scale scan very well, so less work is needed in post processing. That they are relatively inexpensive in bulk rolls doesn’t hurt either.
Rodinal Developer – Representation of film grain in a scan of a black and white negative can be tricky. Rodinal is head and shoulders above all the others I have tried in this regard.
Ilford Rapid Fixer – A non-hardening rapid fixer is required with the Ilford method of washing film. Ilford Rapid Fixer is widely available and reasonably priced.
Distilled Water – I wrote earlier about my use of distilled water. All I will mention here is that I use a plain distilled water stop bath and no wetting agent in the final wash.