Create a database of the CDs, back them up digitally and then decide...
it depends if you are going to listen to them... I would keep all/most of them as my tastes over time has changed...
Ten years ago there was NO way I would listen to (much less buy) Bing Crosby, Henry Threadgill , etc...
It also depends on your age... If you think you will grow with the collection.. Keep it...
If you were going to donate it.. I'd recommend a public library... that way other people can have access to it. When I donate my CD's that's where they go...