I prefer one with a freezer on the bottom. It gets used the least, and puts the storage area at a more reasonable height. I'm 6'2" and I *HATE* bending down to get stuff at the bottom of the refrigerator. I'd love to have a water/ice dispenser in the door, but I couldn't find one with the freezer on the bottom. I'm sure they're out there now, though.
As for the efficiency, better efficiency is always good, but not as much as they might make it seem. On Long Island, when you're heating your home 4 months of the year or so, the energy cost of the refrigerator is greatly reduced. It is a heat pump, moving the heat from the food you put inside, back out into the kitchen, and quite efficiently. The energy used by the refrigerator shows up as heat that reduces the load on your heating system (actually the same with ALL electric appliances that don't use hot water). If you reduce the consumption of the refrigerator, your heating system will have to make up the difference.
The big gains from better efficiency come during the cooling season when your refrigerator is consuming less energy (producing less heat). This reduces the load on the a/c, and gives you a "cooling" bonus (again, same with using any more efficient electric appliance).
Basically, I'd get the most efficient one that gives you the features and style you want at a price you can afford. Isn't appliance shopping easy?
