I grill my own. Better than any place I would go to eat.
For one thing, I don't use all that disgusting glop (condiments) that the fast food chains use. Probably to disguise the fact that the burger itself is a tasteless disc that was probably sitting in a freezer warehouse somewhere for five years.
I make 8 ounce patties and all I season them with is a little bit of salt and pepper. Six minutes one side, flip, six minutes on the other. Perfect medium-rare.
Put on a brioche bun and add a thick slice or two of your favorite cheese.
That's it. No need for mustard, ketchup, pickles, wilted lettuce and all that other stuff.
What you get is a perfect juicy burger. And all you need is one.