The Australian Consumer Association recently published a list on Computer Energy Costs for various home gadgets such as your computer screen, DVD player, cordless telephone, gaming console, laptop etc.
Interesting with this list is that it shows how much energy these gadgets consume weekly, monthly as well as yearly, even when they are supposed to be off.
According to the study, the Sony PlayStation 3 consumes 33.34 kWh (weekly consumption) when on and playing a game. That is more than a Plasma TV who uses 29.68 kWh when on and playing a DVD.
When the same game console is off (back switch on) it still consumes 0.30 kWh. Microsoft's Xbox 360 consumes 0.40 kWh when off and 26.00 kWh when on and playing. The Nintendo Wii is a bit better, it consumes 3.14 kWh when on and playing a game. But it consumes 0.32 kWh when off (WiiConnect24 is off). That is more than PlayStation 3.
The only way to be sure these energy hungry gadgets don't consume energy (and your money) is to make sure they are switched off and unplugged when you are not using them.