Subway 229 Chrystie St., New York

When he cofounded his first sandwich shop in 1965, 17-year-old Fred DeLuca planned to use his profits to pay his way through medical school. But the combination of quality ingredients and friendly service at the shop—then called Pete's Subway—proved so popular that nine years later, he and his partner found themselves in charge of 16 locations across Connecticut, and Fred left behind his doctoring plans for a career in business.

Today, Subway serves breakfast, lunch, and dinner and boasts more than 38,000 locations around the world—almost as many shops as there are sightings of Elvis buying cold cuts. At each location, staffers pile sliced ham, marinara-slathered meatballs, and other fillings into halved loaves of bread before customizing handhelds with tomatoes, shredded lettuce, and other healthy toppings plucked from chilled containers behind the counter. Subway’s website also facilitates health-conscious eating by listing each item's nutritional information online.