Interestingly enough, Xbox 360 is also the most energy efficient console, squeezing higher performance out of each watt: 61.21Mhz / 1 Watt. The GameCube ranked second at: 30.81Mhz / 1 Watt. Also worth noting, for you penny pinchers, if you unplug your consoles in-between uses, you'll likely save a couple bucks worth of 'leaked' energy annually -- that goes for cell phone chargers and other electricity-dependant devices too. But please, don't unplug the 'fridge before going to bed.
Joystiq readers are environmentally friendly
Joystiq poll: Do you leave your game console on standby?