There is a game called Chichi Robo for the gamecube but you aren't a giant robot. You are a small robot in a house and you have to keep the house "happy". Its a very good game. They might make a version of it for the Wii.
click here to learn all about it
its just an action adventure were ur in this mech suit but its not bulky it agile and it really badass totally owns all other mech games but its been a while since I've played it but I remember it was badass haha