By far the best burger you can get in a fast food setting. And the fries are killer. Seriously no fast food burger compares. Don't expect cheap though, a good sized burger with a small order of fries is plenty of food but it'll cost you $10 or more.
To In and Out fans, the burgers are better, with more options and there's NO COMPARISON as far as the fries go. In and Out fries are terrible.
Smashburger is the closest comparison, with nicer dining rooms and great burgers (plus beer) but, again, the fries are strings of cardboard. Their soft drink options also suck by comparison.
I only wish they had a drive-thru, but it wouldn't work since they grill them fresh and there are tons of topping options.
If you see a Five Guys, stop and get one. The Scottsdale location at Greenway is convenient, clean and awesome.