I have my qualms about each company, so I'll visit each of these threads and tell you my opinion.
With Nintendo, frankly I'm upset because of what we could've had if their systems were a bit more powerful under the hood.
A game like Zelda: TP on the 360/PS3 could have awesome physics, massive numbers of enemies on screen, gorgeous animations, HD textures, 5.1 surround sound, HDR lighting, etc. It would make the game, not only great to play, but that much more immersive because of how ridiculously beautiful it was.
Little Big Planet ... you can't tell me that game doesn't appeal to the Nintendo audience. Technically, it would have to go through some serious downgrades to work on Wii hardware.
And with more power, more games would cross-platform. We could have Rainbow Six games, GTA, Devil May Cry, and on and on and on.
It would be the system to bring everyone together, Graphics and Gameplay. Wouldn't it be glorious?