i started out playing with the PS2 -> GCN doodad. It worked great except when th egame says " press B to crouch up on that guy and subdue him silently" but i didnt remember which button on the PS2 is really B, so I end up pressing triangle or something and blasting him away and all his guard buddies heard and come out to help him.
After a couple times of this, I switched to the classic contoller and its kicking ass.
The one thing exciting me most when I saw the advertising for the Wii, was the ability to play FPS with the nunchuck+Wiiremote.
That was a revelation for me and probably the highest selling point for the Wii.
As much as I loved playing GE on the N64 with analog controls, I'll be damned if I'd go back and use the CC for the Wii version , especially since the pointer controls are so highly customizable in this game !