The Rodeo Drivethrough. Best damn burgers ever. Alas, they are now gone. But I barely count burgers from most fast food joints as burgers.
Five Guys. Great Fries too. Just carry a bag of them in your car or 5 minutes and you car will smell like their fries for days.
I'l say Swedish hamburger chain Max. The only chain that has ever made a McDonalds joint close due to competition. Other then that I'd say Burger King (don't know what this talk about soggy burgers is, they're great here in Sweden), or ulitmately a burger in just about any grill in the US.
I lived on those things for an eight month cruise once. I was a flight deck trouble shooter and my meals consisted of two sliders stuffed into my tool pouch and back to the line shack to stow them till I had time to eat. If I was lucky I’d get to eat one of them while it was still warm, most times I suffered them cold!
Local place called Crown Burger. A crown burger, beef, 1/4 lb of pastrami, cheese and lettuce, chili cheese fries and an extra large coke. Damn good stuff.
If you're ever in Amarillo, Texas, look up the world-famous Arnold's Burger. They're HUGE, greasy, and amazingly delicious. You can even get them for parties or families (yes, that burger is in a large pizza box).
As a rule I don't eat fast food. However, every year or two I'll find myself on a long car trip where I haven't packed myself some healthier options. When that happens it's McDonald's for a quarter pounder with cheese and a small fry.
Burger Baron. A small but long-lived Canadian chain, founded in 1957. The only fast-food place I've ever seen that serves deep-fried mushrooms.