Gamecube:

Luigi Mansion 2 

Gamecube - Resident Evil 4

N3DS - Resident Evil Revelations

Super Mario Sunshine Gamecube

3DS - Super Mario 3d Land

Gamecube - Mario Kart Double Dash

3DS Mario Kart 7

Gamecube Fire Emblem Path of Radiance

3DS Fire Emblem Awakening 

Gamecube Super Smash Melee

For the future - 3DS Super Smash Bros 4

GameCube.

The only 3DS game that really stacks up to Rogue Squadron, RE4, etc. is Revelations, and that's because of the shader tech.

Gamecube. Though I'm told the 3DS is almost as powerful.

Those GC screens aren't Dolphin are they?

Gamecube, but Xbox One is more powerful than GC so HAH!

I dont know about specs but in terms of visuals id say they are pretty similar.

The GameCube is more powerful, but the 3DS is not that far behind in terms of visuals either ( just look at Resi Revelations)!

I like the 3ds better cause I think the art direction in the 3ds games is way better than the gamecube even though the GC is more powerful

I don't know about their exact specs, they look pretty similar though. Gamecube might just edge out 3ds.

Its very close but maybe 3DS just?

I'd say Gamecube, but after seeing these comparisons i go with 3DS...
Atleast i like the graphics more!