Does anyone know of a PC supplier (or component supplier) who quote the actual power comsumption of their PCs?

I'm looking for a moderate powered PC to run 24 hours and thus want reasonable power consumption but I want a bog standard PC not a mini ITX (or Shuttle) system as they seem expensive for not much gain.

To my surprise my new Asus P5Q-VM motherboard system with 8GB of memory and 500Gb hard drive only consumes around 60 watts. That suggests that it should be possible to get a lower specification system down below 50 watts or so which would be quite acceptable.