I've been collecting comics for 30+ years, and because I was an army brat, I've had to give up all of them more than once when we had a weight limit to meet on our move.
Most of the time, we gave them to the children's wards at hospitals. Other good recipients for donations are your local Veteran's Hospitals, libraries, or military bases- the troops are ALWAYS starved for quality entertainment, especially of the portable kind. Libraries and other organizations can sometimes use them for auctions.
And YES, you can get a tax credit on donating them! The benefit is that you get FULL valuation for your donation, as opposed to selling them for about 50% (or less) of valuation. If you're really trying to move them, you might find that taking them to a book reseller is quickest.
Some rules, though:
1 It only makes sense if you itemize your taxes. If you don't itemize, you're just as well off trying to sell them.
2 Make sure you make a detailed list and approximate valuation of your donation, in case you get audited (unlikely, but possible)
