I´ve registered the collection in Word documents, one for each letter of the alphabet, and then one section for each composer there. My collection is mainly in the old media of LPs and CDs, but I also have digital files.
The good thing is that one can design it according to one s taste, and add for example Wikipedia- or other biographies and material etc. in the entries, and that it is clear and comprehensible;
the bad thing is that there are basically no search options, no other categories than composers, and that it is overall very time-consuming.
I used to keep a basic listing according to record labels too, but gave it up, since it meant spending more time.