[quote name='AlphakirA']Gamestop does give cash at certain stores, it is 20 or 30% less however[/quote]ALL GameStop/EB Stores stopped giving cash back for DVDs early this year. If they do a cash trade for anyone on DVDs, they get a corrective memo from corporate shortly afterwards. They give cash back for games, systems and accessories for 20% less than the trade-in value. For DVDs, it's store credit only.
I trade DVDs regularly with MovieStop and CD Warehouse.
MovieStop's locations are limited--they currently have between 30-40 stores. They don't have a website, but if you search for MovieStop on yellowpages.com you can find about 20 store locations. They have the best trade-in deal going currently: if you trade in any 4 DVDs (must be from major studios/distributors) you can get one of that week's new releases free... up to a $19.99 value. Or you can put that same value towards a pre-order. They offer cash-back as well, but the same promo doesn't qualify.
CD Warehouse offers cash back only, and depending on what store you go to they can be really picky about the condition of your discs. They also refuse trades if they have more than 2-3 copies of certain titles currently in stock. Check to see if they have a location near you at cdwarehouse.com