I think for a chain of burger joints, Steak N' Shake is among the best. Their "steakburgers" live up to their claims in quality in their rich flavor and variety (there's so many different types to choose from like the new jalapeno crunch steakburger, frisco pattymelt, and guacamole steakburger). There's also a smorgasbord of really good milkshakes to choose from, and you can even mix and match some flavors!!
Aside from the good food and good service, the restaurant's vintage atmosphere adds to the charm of the place.
If there's a Steak N' Shake in your area, I suggest you dine there the next time you want to go out for lunch.