I don't think you're gonna make a profit on them dude, unless you didn't pay much for them on the first place. I gave up selling my games totally it was hardly even worth it. I just give them away, as the ones I don't want are usually the ones nobody else wants either.
Unless it's a title that just came out/still in demand and you stick it on eBay (which I know you don't wanna) but sometimes people are actually weird enough to end up paying more for a used game then they would to buy one new on there. OR if you've got a rarer collector's ed or just a game that people are after but is out of print, you can sometimes shift these things on Amazon or eBay for a profit, I mean look at this
http://www.amazon.co.uk/Atlus-RR530...8&qid=1380283446&sr=8-3&keywords=rule+of+rose
But if it's a game that nobody much cares about, you'll be lucky to recoup your postage and waste of time posting it. Check out what other people are selling the games for and see what the general value is, then decide whether its worth flogging them online or at a yard/room sale thing. I think I tried to set up a game exchange thread on this forum once, but there was zero interest, maybe you could try that on other forums, it works on a movie forum I know of pretty well.