There is a great article from HCW that is comparing the power consumption of each console in an array of tests. The tests are pretty comprehensive showing (with graphs) what each draws while playing a game, playing a movie, sitting idle and even while the power is off.
The guide lets you know why leaving your PS3 running idle is crazy thinking and how sparingly the Nintendo Wii uses juice, even running at full boar.
Someone should point Greenpeace to HCW's article. Electronic consumption is part of a green initiative, but Greenpeace's "Guide to Greener Electronics" only covers eliminating hazardous substances and recycling in their products . Adding electronic consumption would surely dig Nintendo out of the hole it has with them.
To read the article in full, visit the link above!