First, I agree that pirated (downloaded) games have little effect on Nintendo's profit, especially in China. Counterfeit games sold at retail price are a different matter, and they could certainly mean Nintendo is losing money, but if a counterfeit game is way sold below retail, no one thinks it's real, they just aren't willing to pay the actually cost of the game and are probably not a lost sale.
On GBA pirating, you can either run an emulator on a PDA or tablet computer (recent ones are probably powerful enough to do so) or get a GBA flash cart, which is completely legal to own/distribute, just it's not legal to put games you don't own on them.
On GCN pirating, (EDIT2: Removed)
Of course, that works for pirating, but not for counterfeit games. By now it would not be surprising to find that counterfeiters had Gamecube disc stamping set-up to create counterfeit discs.
EDIT: Bill: The title was probably cut off by the quote mark due to some sloppy coding.
EDIT2: I apoligize, I just reread the rules, and my post was breaking them. I thought I would be fine because I didn't post a link to a ROMs site.