To your main point, I really like In n' Out. I'd love to have one close by.
Five Guys is a terrific hamburger spot. They're expanding at a pretty rapid pace and I'll be surprised if they're able to maintain quality.
I'm not as sold as you are on Fuddruckers. To me, Fuddruckers is about the same as Red Robin or Ruby Tuesday. A decent, but overpriced, burger.
I'd also move Crown Burger into the top tier. I love the Crown Burger. I have an acquaintance who regularly travel to Hill AFB and, though not a native Utahn, always makes a visit to Crown.
Another place I really like is Culver's. It's a midwest chain and is known for their butterburgers and frozen custard.
http://www.culvers.com/about/default.aspx