I like the first one. Compared to GameCube's, it's more...it has more sizzle, as Dennis Dyack would say. The GameCube logo was extremely, extremely cool....but it wasn't very attention grabbing.
Though the logo doesn't go very well with the text. Actually, the lmockups really illustrate that "Nintendo Revolution" is way too long of a name. Maybe "Revolution from Nintendo" isn't such a bad idea after all...