Burger King's new "Men in Black II" promotional tie-in sandwich, the Black Stack BBQ Griller, is quite good. It's like their back-porch grillers, two patties on a "deli-style bun" or some such. Also comes with a couple kinds of cheese and BBQ sauce.
It could really use grilled onions.
These "grillers" (no relation to the vegetarian "Grillers" they used to serve) are supposed to taste like they were grilled at home. They're actually not bad. I think the one with smoked cheddar is the best of the bunch.