Yea it is Gamestop. And did some more looking around and found this.
http://www.gamestop.com/gs/specialty...ns/offers.aspx I think you'll be interested in this one
$20 Extra Hardware Trade Bonus
Trade-in your used hardware (PS2, DS, Xbox, PSP, 360, Wii, PS3, GBA SP) and receive $20 extra trade-in credit!
Expires: 8/10/08. Gamecube, Gameboy Advance, and Gameboy Micro excluded from offer. Offer not good on cash trades. Trades must be in full working condition to receive full value. Hardware must have all necessary components for trade. Cannot be combined with any other offer. Trade-ins subject to manager approval. See store associate for details. No dealers.