If we want to talk about consistently good burgers at almost every location and taste, nothing beats In-N-Out. And btw. I'm talking about burgers and not fries. Size is relative, the size is the correct burger size. Burgers were established as a nutritious staple of the American diet at a time before vast consumerism in the 60ies and 80ies.
So In-N-Out wins for me.
LA people got a choice of Umami,
Apple Pan and Father's Office as well. All really good burgers. And of course Fatburger.
I think Shake Shack is super overrated and Whataburger is alright but..aeehm.
Five Guys is only good in Maryland. Everywhere else I had it, it was ok-terrible.
Btw. the best burgers are/were sold around Taksim in Istanbul for 3 Lira.