In-N-Out is far better than anything we have in Connecticut, unfortunately I only get to go there when I head to Phoenix every March. I do not like onions so White Castle is not for me. Sonic has decent burgers.
Here in Connecticut the best is Wendys for "fast food" burgers, but there is a small place in Meriden,CT. that makes the best steamed cheeseburgers I have ever had anywhere.
Also, back in the late 80's I remember going to a burger joint in Southern California that put onion rings on their burgers....that was delicious.
DaPup