Preheat a grill to medium high. Make the salsa: Combine the tomatoes, lime juice, sugar and 1 teaspoon salt in a small microwave-safe bowl. Microwave 2 minutes, then stir in the cilantro, red onion and jalapeno; set aside.
Toss the corn with the vegetable oil in a large bowl; season with salt and pepper. Form the beef into four 1-inch-thick patties; season with salt and pepper. Lightly brush the grill grates with vegetable oil. Grill the corn, turning occasionally, until marked and tender, about8 minutes. Meanwhile, grill the burgers about 4 minutes per side for medium rare. Toast the buns on the grill.
Sandwich the burgers on the buns with the guacamole and salsa. Serve with the corn.
Photograph by Charles Masters
Recipe courtesy of Food Network Magazine