I would agree that if you don't need whatever money you would recoup from the sale and you know a budding audiophile, then a late Christmas present would be the way to go. However, if you do wish to sell them, my first choice would be US Audiomart, Canuck Audiomart if you are up north or Craigslist.
I have used both and both have their pros and cons. Audiomarts have a more knowledgeable clientele and less idiots. Craiglist saves the hassle of shipping, but there are too many people that either don't know anything or want it for nothing.