I did my fridge recently. Too bad I'll never know how much power it saved cause I definitely won't buy a Kill-a-Watt for this. Can't see anything from the front:
Bubble wrap, duct-taped on the side:
I'd be happy to drop the fridge power bill by 10%. I can say, that side definitely doesn't feel cold to the touch anymore. I'm sure the effect will compound, as well, due to less of a load on the AC.