Top 10 energy efficient desktop PCs

6 Aleutia E2
£200
8 watts
This PC runs the Ubuntu Linux operating system and is designed to help spread computing in the developing world. But it should also be fine for basic web tasks at home. Power consumption is insanely low, though as our compatriots at ZDNet.co.uk noted when reviewing the E2's predecessor, it took twice as long as another system to play a YouTube video -- so some of your energy savings are cancelled out by its poor performance. On the plus side, it's so small you can mount it on the back of a monitor.