Being from Chicagoland, there are no In-N-Outs anywhere near me. So anytime I travel out West, I make sure to get to one at least once. The burgers are pretty good, and they let you customize a crazy amount of ways. (Granted you need to know the "secret" menu, but any google search can give you a good idea of the options out there and you can figure out your order from there.)
The thing that always impresses me about In-N-Out is that the food is all fresh. You can normally see them cutting the potatoes for the fries right before making them. (I also might be the one person in the world who likes In-N-Out's fries just regular straight up, no animal style or well done, but you can also read up on your options there and customize it to your taste.)
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.