OMG I wish I had this deal a few months ago... Just upgraded from the old 360 to the 360S...
Xbox 360/PS3 trade up to new
Get a minimum of $100 in-store credit when you trade any model Xbox 360, or a minimum of $150 in-store credit when you trade any model PS3 toward the purchase of a new Xbox 360 or PS3.
Full trade value must be applied toward the purchase of a new PS3 or Xbox 360. 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. Offer vailid in the United States, Puerto Rico and Guam only. Void where prohibited. GameStop, Inc. reserves the right to cancel, terminate, modify or suspend the offer for any reason without notice.