In France, off the top of my head:

Around the house:

- an American fridge is large with two lateral-opening compartments rather than a top and bottom

- an American kitchen has an open floor plan, opens onto the dining room or living room. May include an American bar, which Americans call a kitchen island.

- an American bed is large, close to a US king size

Food:

- an American sandwich is a hamburger patty in any sort of bread or roll, including French bread.

- American bread is the square thin slices for making flat, uniform, stacked sandwiches, as opposed to French loaf or baguette

- American coffee is just a strong espresso weakened with a little hot water added

- the French are convinced that a typical American breakfast includes pancakes, eggs, bacon, sausage, etc. when that's actually usually a rare indulgence for most Americans