Depends on what you are looking for. I do energy testing on PC's. Depending on how you use a system, the lower power capabilities can really help. In a business, where there are many systems running, it can make a difference. At home, you probably will not notice so much(although the aggregate of thousands of systems using power on the grid would make a difference in overall usage).
The thing about Energy Star that I find kind of interesting, is nothing really turns off these days. For instance, if you turn your TV off, it only goes in to a standby/sleep state. It is still consuming power. For your remote to work, some minimal circuitry must be powered to detect the remote. Even the switch on the TV has to be sensed; it is not like the old days when the switch actually cut all power to the appliance.
That means, the dryer, washing machine, vcr, tv, microwave, dishwasher, ect ect ect all draw power, even when they are turned "off".
In most cases I would not replace something just for the power savings. But anything new these days, I would look for the lowest power ratings.