nicnap;
I have given some away to those who need them, but most of the ones that I keep are full of my notes, and so I assume that no one else would want them.
You would be surprised at who may appreciate a bible with many notes.
Many of my friends when they became Christians wanted to read through the notes in my bibles..one of which was a convert from Mormonism, I gave him one of my Bible's filled with my notes..He was amazed and encouraged that God still speaks to man today and how many OT passages still relate to today's world.
Consider if you donated even one of those to a Missionary to take overseas to leave with a new convert or a young pastor..who doesn't have all the commentaries that we have available here, and the wealth of knowledge that is written within the pages--of things God has taught you over the years.
My kids read through the personal notes in my bible, and then look at me and say "wow, God sure has taught you a lot hasn't He?" I say, "yes, but I still have a LOT to learn."