Subway - 2421 N Clark Street, Chicago

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 restaurants number over 34,000 around the world. 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. Salads free crisp veggies from bread's overprotective embrace, and crunchy baked chips or apple slices accompany entrees to tables. Subway's website also facilitates health-conscious eating by listing each item's nutrition information online.