my favorite burger place is called cheeburger cheeburger. We have 2 in the st louis area, it has a 50's diner feel the prices are a little steep but the food is so amazing that its worth every penny. They have a 1 pound burger challenge that if you can finish it you get your picture on the wall. So far I havent tried 5guys but my wife, who has also been to cheeburger cheeburger, said there wasnt even a close comparision.
http://www.cheeburger.com/home2/index.asp
LOVE IT!!!