I Don't Know What To Do...

This isn't some big dilemma or anything but I'm not sure what to do. I'm going in on Monday to trade in 14 games at GameStop, only 7 are mine, and a memory card, which doesn't work...well...Anyway I'm getting rid of Pokemon Colosseum (maybe I'm not final on that one), Wave Race Blue Storm, Tony Hawk's American Wasteland, Gladius, and Ultimate Spider Man on GameCube. Red Steel and Monkey Ball on the Wii are gone. And My sister is "letting me" trade in Mario Party 5, Smash Bros. Melee, Animal Crossing, and Pokemon Channel for GameCube, and WarioWare Touched and a Spyro game on DS. They got this thing going on where if you trade in 5 or more games you get a bonus 30% so I figured now was the perfect time to trade some stuff in. I don't know what to do though. I'm getting 55 bucks on top of that for babysitting and I was thinking about a game or I could save it all for a 360 or PS3 or PSP. What do you guys think?