[Katana]

If your a PC gamer who likes to play the newest games on high specs then power usage is probably not a massive concern, if you don't play games but don't want a laptop interface, buy a laptop (spec doesn't matter much if you don't play games), stick it somewhere around you desk, hook it up to a monitor, keyboard, mouse, speaker system and you have a low power system. I've tested a few laptops with a power meter and never seen them draw more than 50-90w on full load, chuck in another 30-40w for a monitor.

I have a Core 2 Duo e6750 with a 600MHz overclock, a Radeon 4870 and 3 hard drives, and under full load (CPU and GPU) draws around 360w, though it idles most of the time around 170w, 150w if i turn of folding@home. I have a 520w PSU with 80% efficiency rating meaning the actual PSU max is around 410w, so my PSU is the perfect wattage for my system.