Wikipedia summarizes the arguments for and against energy star nicely in the appliance section. I'm not entirely sure the program does anything useful except print stickers but I suppose standardized stickers are worth something too.

I've got a pretty passionate hatered for "efficient" appliances though. Energy targets seem to encourage manufacturers to shittify a product core function and create toilets that don't dispose of shit, washers that barely wash, dryers that leave clothes slightly damp... etc. I'd rather just pay the extra energy cost and have things work correctly. I guarantee the most people aren't going to choose the damp setting on their dryer if there is a dry setting, but programs like energy star encourage manufacturers to only have the damp option.

As of early 2008, average refrigerators need 20% savings over the minimum standard. Dishwashers need at least 41% savings. Most appliances as well as heating and cooling systems have a yellow EnergyGuide label showing the annual cost of operation compared to other models. This label is created through the Federal Trade Commission and often shows if an appliance is Energy Star.[16] While an Energy Star label indicates that the appliance is more energy efficient than the minimum guidelines, purchasing an Energy Star labeled product does not always mean one is getting the most energy efficient option available. For example, dehumidifiers that are rated under 25 US pints (12 L) per day of water extraction receive an Energy Star rating if they have an energy factor of 1.2 (higher is better), while those rated 25 US pints (12 L) to 35 US pints (17 L) per day receive an Energy Star rating for an energy factor of 1.4 or higher. Thus a higher-capacity but non-Energy Star rated dehumidifier may be a more energy efficient alternative than an Energy Star rated but lower-capacity model.[17] The Energy Star program's savings calculator has also been criticized for unrealistic assumptions in its model that tend to magnify savings benefits to the average consumer.[18]

Another factor yet to be considered by the EPA and DOE is the overall effect of energy-saving requirements on the durability and expected service life of a mass-market appliance built to a consumer-level cost standard. For example, a refrigerator may be made more efficient by the use of more insulative spacing and a smaller-capacity compressor using electronics to control operation and temperature. However, this may come at the cost of reduced interior storage (or increased exterior mass) or a reduced service life due to compressor or electronic failures. In particular, electronic controls used on new-generation appliances are subject to damage from shock, vibration, moisture, or power spikes on the electrical circuit to which they are attached. Critics have pointed out that even if a new appliance is energy efficient, any consumer appliance that does not provide customer satisfaction, or must be replaced twice as often as its predecessor contributes to landfill pollution and waste of natural resources used to construct its replacement.[19]