sorry to say this, but u all simply just didnt do enough homework

according to coolermaster website, this is their 3 psu's model efficiency.
iGreen series : 81% (100W) / 85% (250W) / 82% (500W)
RealPower series : More than 75% efficiency at typical load operation
eXtremePower series : More than 70% efficiency at typical load operation

its stated clearly enough which are good ones.
As mentioned by few forumers as well, the price factor really counts when buying psu as well.

btw, i have iGreen 600W and im truly satisfied with it on C2D system (oced), 9 fans, 2 hdd, 2 cd/writer, 1 6800gfx