Custom Robo is a pretty decent game. I only played through the first campeign, but there is a second campeign that you can play through afterwards, and should take up a large chunk of time. Plus the multiplayer is epic, so that's an added bonus. Also, Animal Crossing is an endless game, I never played it on the GC myself, but it has garnered many good reviews. Finally, Pikmin 2 is a great game, and you can spend tons of time collecting all of the items in each of the levels. Thank you :D