Starting today and going until Tuesday, GameStop and, as far as I know, ebgames are giving 10% more on all trade-ins of games, dvds, and accessories. The 10% bonus is stackable with the more card and I guess eb's card also, for a total of 20% more trade-in value.
Sure it's not as good as the tiered trade-in offer GameStop ran a while back, but who knows when that'll return?