I would say Top opening (chest) fridge vs regular fridge. The cold air doesn't flow out.
I would say only visit it once per day or at least as little as possible.
Store stuff outside the fridge (carrot, cabbage, etc)
Keep the Fridge as full as possible, so there is less air to lose/chill daily.
You can also make your own fridge too, buy the outside compressor+internal chiller from a boat shop vendor online.
As for the most efficient fridge in USA Daewoo FR-1020ARW $300.
Here is the full list https://www.energystar.gov/most-efficient/me-certified-refrigerators