The WII is 2x more powerfull then the GC, the GC's graphics IMO were close if not on par with xbox/PS2.
The games on the 360/PS3 are mostly realistic looking games, so its hard to compare graphics.
A WII game could achieve the visuals equal to that of the 360 or PS3, it takes very clever art designers, look at "conkers bad fur day" for N64, that game really push's the 64 to its limits.
But we have to remember, the 360/Ps3's are pretty much high end gaming PC's, whereas the WII is not.
The games on the 360/PS3 are mostly realistic looking games, so its hard to compare graphics.
A WII game could achieve the visuals equal to that of the 360 or PS3, it takes very clever art designers, look at "conkers bad fur day" for N64, that game really push's the 64 to its limits.
But we have to remember, the 360/Ps3's are pretty much high end gaming PC's, whereas the WII is not.