I honestly can't decide
I have wayyy more Wii games than GCN games (100 vs 50), but Gamecube has tons of my all-time favourite games. Wii has Xenoblade though, which is better than anything on the Cube.
I'd probably say Gamecube > Wii, but as far as Nintendo offerings go Wii definitely beats Gamecube.
Either way they're both superior to N64 of NES.
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