Oh man, for burgers it almost feels like apples vs. oranges. For the burger itself, Five Guys all day. For the pure "burger" experience, I lean towards Red Robin. Damn, that's tough.
Fast food burger-wise, Five Guys/Smash Burger/Shake Shack, all are a huge tie to me.
And west coast peeps, don't try to hype up In-N-Out. Needs more seasoning.