We might be a little bit biased about this logo, but only because the Nintendo Gamecube was such a great console. It was released during an era when the Sony PlayStation had started to eat into Nintendo's share of the market, but it was a strong performer with some great games, and it arguably never got the recognition it deserved. Nor did its fantastic logo, which is one of Nintendo's best.
The logo is essentially a cube inside a cube, and bears a strong resemblance to the device it was designed to market. The geometrically pleasing logo has more flair to it than that though - the harder outline of the cube makes the shape of a 'G,' and within it, the white space takes on the form of a 'C.' It's spelling out the initials of the platform for you, and using three dimensions to do it with. Very clever!