http://www.energystar.gov/index.cfm?...ch_dishwashers
unfortunately the sort by water consumption doesn't seem to be working properly. You can get the excel version and sort it yourself though.
Looking at the list real quick it looks like you can get some energy star models that use half the water of other listed ones and they tend to be quite efficient on electricity. Bosch has a few at 2.22 gallons and 200 kwh/year that look excellent in the list definitely dl and sort to verify that though.