Whenever my family hosts Europeans, we always take them to Buffalo Bob's BBQ in Lawrence, KS. It is hilarious watching their faces as the food is delivered--platefuls of fries, huge portions of BBQ, and half-gallon glasses of pop. They always look so amazed at the amount of food and drink they get.
We had an exchange student who was equally amazed. He couldn't get over all-you-can-eat buffets, free condiments, free refills on drinks and keeping the glass, plate sized steaks, and doggie bags.
Then there is the opposite reaction when Americans eat in a European restaurant. An acquaintance of my husband's was having a birthday and wanted to eat at a European restaurant (obviously because he wasn't paying). My husband said the food was overpriced and the portions really small (this from a man who doesn't really eat much to begin with). My husband came home later and filled up on my homemade bread.