Five Guys is chain that started in DC and recently opened in Philly. I've got to say that for fast food joint, they really hit it out of the park. Fresh, never frozen beef smashed on the grill, loads of topping options. I had a regular Bacon Cheeseburger (which is actually a double burger) and because that was so good I also got a Little Cheeseburger (which is just a single burger). I was literally making "mmmm" noises every bite. So delicious. And I particularly liked how the bacon was chopped into bite-sized pieces, making it easier and less messy to eat.
The fries were a little underdone, but that was probably just because there were about thirty of us showing up at once (a fast food nightmare) and they were trying their best to keep us moving. As my friend Dave said, we were pretty much a flash mob.
The only downsides were the prices (a bit higher than I would have expected) and the overly bright lighting, although the steady stream of classic rock helps alleviate the light to some extent.