There's a recent update to the "Who's Who In Power Supplies" over on Tom's Hardware:http://www.tomshardware.com/reviews/power-supply-oem-manufacturer,2913.html
...How do you identify a bad power supply before buying it?Extremely high wattage claims at comparatively low prices are suspicious. There are simply no decent 750 W power supplies for $50. For every product class based on performance and features, there must be a minimum price. When a product is significantly below that price, be cautious. You can get a "400 W PSU" for $20, and such fire hazards are installed in budget PCs every day by unscrupulous companies that know exactly the risk they're handing off to buyers...