Now on average amazon will offer about twice as much for trade in credit as gamestop and the gift card you get can be used to purchase anything in the store not just games. The downside is that it takes about a week or 2 for you to get your credit and you have to send it off. (the shipping is free but you have to buy a small package to ship it in)
http://www.amazon.com/Video-Games-Trade-In/b/ref=sv_vg_9?ie=UTF8&node=979418011
http://www.amazon.com/Video-Games-Trade-In/b/ref=sv_vg_9?ie=UTF8&node=979418011
