According to a study published in 2018 by the Centers for Disease Control and Prevention, more than 36% of American adults ate fast food on any given day between 2013 and 2016.

However much we might know about the potential health problems caused by the consumption (or at least overconsumption) of fast food, and no matter how vigorously we might claim to disdain such fare, the fact is that a lot of us find it pretty irresistible at least some of the time.

As with most indulgences, the best game plan for enjoying fast food is simply not to overdo it. And an occasional cheeseburger or pizza or bucket of fried chicken will probably not not kill you. (Speaking of burgers, this is the best burger joint in every state.)

If and when you do join the line at McDonald’s or pull up to the Sonic Drive-In window, what should you choose? That’s a matter of personal taste, of course, and there’s plenty of variety out there, even beyond the obvious. But every chain has an iconic offering or two – foods that pretty much define them, and that few people can resist when they place their orders.

Click to see the most iconic items at America’s biggest fast food chains

Drawing on a number of sources, 24/7 Tempo has used editorial discretion to choose the single most iconic food item at 18 of the nation’s most popular chains. These iconic choices are either the things most ordered or the original offerings that helped make the chain’s reputation – or both. (Here’s a list of the most popular fast food chain in every state.)