Well everyone, there's no way to be right or wrong, so go nuts.

Imagine if, Nintendo had released NSMB on the GC, with very few differences (besides being slightly less graphically impressive and lacking motion control) For the sake of this, assume that it was launched at about the same point in the life of the GC as it was on the Wii.

FYI 6.28 million is the sales figures of Super Mario Sunshine

6.28-10.

Same number as Mario Kart! It's a powerful game, but not a miracle maker!

It would definitely have been big and driven hardware sales. Though, to some degree NSMB is a better fit on Wii, the controller suits better and the console itself is already in with a wider audience.

I'll say 15-20 mill, which is much less than it'll do on Wii.

It would have been big, but not as big as you're giving it credit for, Demotruk. Remember - GCN didn't have the simple controller design that's a major throwback to the NES, and it didn't have motion controls.

It would have been assuredly less than 10m, but it also would have been the GCN's best-selling title and probably would have finished up in the 8-9m range.

7-8 million, maybe 9

A lot depends on when it was released.
If it came out around the same time as the DS game, that was late in the GC lifespan (months before the Wii was released).
So by that point, there was no hardware to drive.

Had it come out in 2004, it might have seen even higher sales.

Mike from Morgantown

I originally clicked 10-15m, thinking just over 10m units, but after looking at the GC's biggest sellers I think it would land in the 9m range, which would put it significantly ahead of the other games.

It would have done great, however, the existing install base is just as important to the games sales as the hardware it moves. The Wii has been incredibly successful (same with the PS/PS2) due to word of mouth. The lower interest in the GC would directly hurt interest in an individual game.

I had pretty similar thoughts to Nordlead, but decided to stay with my initial thought of 'just above 10 million'

Dunno, it wuld have moved hardware like crazy so I put it 15-20

I agree with comments about GCN controller complexity holding back sales (and maaaybe the lack of motion control although I'm not sure that would have bothered people that much). That said I think it would easily have been the top seller and would have driven hardware.

I think it would have crossed the 10 million line, but probably not by a lot - 10 to 12 million. I think it also would have pushed an extra ~5 million GameCubes.