I have not had the burgers at Chicago Brewing, but I can second the burgers at 777. Back when the Upper Deck was open at the Las Vegas Club, they had a really fine burger, too.
And as for Five Guys, I'm from the East Coast. The first time I ever went to Five Guys was at one of the original locations - a little dive in Alexandria, VA. This was before they sold. The new owners started franchising.
Most of us who have been to one of the original stores say we won't go into the franchised outlets for at least 15 years, until enough crud builds up on the grills. That having been said, their burgers are great, the hot dogs are even better and the fries are out of this world. Every day, they have a little sign up that says where today's potatoes are from. And you can get them Cajun seasoned.
It would be great if they'd put a Five Guys downtown, or maybe even a Steak and Shake.