Overusing Ice
Many foreign countries don't ice their drinks at all, but Americans will often ask for a glass just filled with ice along with their drink. Room temperature beverages are a cultural norm in places like France but an insult in the United States. There's a reason even hotels sell bags of ice here.
Listing Drug Side Effects
The United States is one of the only places whose healthcare system allows you to request specific drugs from your doctor rather than them referring one to you. The US is also one of the only places that advertises drugs on TV and lists all of the lengthy side effects in commercials.