http://www.idealo.co.uk/cat/2620/freezers.html also - for example - lets you search by 'annual energy consumption', which is useful.
It's important to compare like with like though.
If you're doing lots of washing, the machine that uses 2kWh/cycle may be better than the one that uses 1.5kWh/cycle, if you need to run the second twice.
Same with hoovers - if one lets you hoover lots more effectively than the other, but uses more power...