Belly-busting burgers rule at this bright and cheery café with multicolored round tables and funky chairs. Every sandwich can be ordered with grilled chicken instead of the usual beef patty, but true believers stick to the real thing and choose from a wide variety of toppings. If you're in the mood for even more calories, the tempting selection of milk shakes is extremely difficult to resist. The only drawback is that there are no french fries -- you'll have to settle for potato chips. Subway: C, E to 50th St.