Actually, yes you can mod your xbox. Don't know about a GCN.

My bro has a friend who has a modded Xbox that we sometimes borrow, has all the NES, SNES and a bunch of N64 roms on it, aswell as Xbox games and PS1 games. You can also rip Xbox games.

"why I've gotta be one of the cool kids just to walk by/
- without being tripped, thrown down on the ground and kicked/
Insulting me for no reason, I was treated like shit/
The teachers let it happen/
I've even seen some of them teachers laughing/
That's why I had a smile on my face when I started blastin/" - Ill Bill - The Anatomy of a School Shooting