I'm sorry, just don't see the big deal about In-N-Out.
I much prefer the burgers at Steak & Shake (midwest US), and I prefer Wendy's to In-N-Out.
BTW, not all that excited about Five Guys, either. Smashburger and Graffiti Burger have been good IME. Haven't yet tried Shake Shack, because every time I go to NYC the lines scare me away.
Bottom line: like most foods, burgers are a matter of individual taste. Vive la difference!