40th Street and Greenway Sonic is the best! The food here is always HOT not warm, and if something is wrong with your order, just talk to the manager who takes care of the problem (only happened once to me). All the employees smile, gives you their name, asks if they can get you anything else, even offer to take your garbage to throw away for you. They show appreciation for your business.
I live closer to another different one that I refuse to go to as the manager has turned grumpy, to bad I will just go to 40th Street for my meals.