Since I was a kid, Fuddruckers has been my favourite place to get a hamburger. Their in-house baked buns are the most delicious I've had and they always cook the burger itself exactly how you order it. I also love that I can put whatever - and however much of - I want on it myself. The seasoned fries are also thickly cut and delicious. Save room for a brownie or cookie - also in-house baked - and you won't regret it.
I always get a 1/3lb. medium-well plain then smother it with hot cheese, honey mustard, ranch or mayonnaise, and shredded lettuce. They'll ask you when you order if you want cheese on it but save the $0.35 and put your own cheese later - they have both normal melted cheddar and nacho cheese at the bar. More cheese and mustard for fries and sometimes I'll even make a little side salad.
Fast, inexpensive, and DELICIOUS.