I'll vote for the All American Burger place in Manhattan, right near Herald Square. You can't beat their turkey burgers, you simply can't beat them at all. And I've eaten a lot of turkey burgers, so that obviously makes me an expert.
One day, if I'm ever in L.A., I'm going to make it a point to try an In-N-Out burger. But at this point, my expectations have been made so ridiculously high that I don't think anything short of a fast-food induced orgasm is going to make me give it a thumbs up.
Also, in Chicago, the Billy Goat Tavern. The original restaurant was the inspiration for the "Che'boiger, che'boiger!" sketch on SNL, and arguably where "Cheeseburger Cheeseburger" lifted their name from. (BGT now has about 3 locations, maybe more) Fun fact: CC isn't allowed (call it a mutual agreement between lawyers) to build any restaurants within Chicago. Turns out that the Billy Goat Tavern kind of relies on the catchphrase for their local marketing.
Anyway, their cheeseburgers are overrated. Good, but overrated. Still no fries, though. Only chips. Also, no Coke (products); only Pepsi (products).