Really interesting comments.
The bizarre thing about my own current 'trimming' is that I'm sure it will result in me listening more to, say, John Lee Hooker rather than less. Hey, I'm listening to him right now!
There was a brilliant magazine/CD collection that came out about 20 years ago called 'The Blues Collection' and you used to be able to get each issue from your local newsagent.
Now each of those guys, from John Lee to Jimmy Reed to Little Walter, had a distinct style, so much so that I believe you only really need one CD from each one. I mean, a 10 CD box set of Bo Diddley would drive you bonkers surely. Knock off those recorded after the 60s (post 60s production never suited the blues), fill in the gaps (the Collection never had an entry for Charley Patton for example) and, voila, that's your blues collection.
Probably not the place to mention it, but my Beatles solo collection amounts to 'Wonderwall Music', 'Electronic Sound', 'Plastic Ono Band' and 'McCartney'. I just can't imagine a time when I'd suddenly HAVE to listen to a Paul LP from 1986. It might happen, but only in the way that Arsenal 'might' win a trophy, i.e. highly unlikely!