Ignore bkarankar.
You want a quality made PSU from a quality makers such as Seasonic, XFX, Antec, and corsair. These companies consistently make power supplies that are reliable and highly efficient (something coolermaster and other companies fail to do).
You want a quality psu with a beefy 12v rail and all the protections etc in case of any problems. It's not all about the wattage, its about the quality. Who cares if its rated at 700 watts but goes to 60% efficiency, all rails way out of spec and a chance that it'll blow up and kill your computer.
Never ever skimp on a psu and always get a quality one from a reputable company.