Royal Caribbean

Johnny Rockets

$14.99 per person cover plus 18% gratuity for lunch and dinner; breakfast complimentary on Oasis Class ships only; milkshakes extra (~$4.99)

For families: Walk-up, no-reservation diner food that toddlers already recognize: a plain burger, fries, and a milkshake. The cover charge stings for a burger, but the all-you-can-eat fries and onion rings make it a real meal to split.