Animal style is fair. Grill with mustard, extra sauce, and grilled onions.
I've gotten to not like the sauce too much. My current favorite is fairly simple.
Hamburger. No sauce. Extra tomatoes, pickles, lettuce.
I started asking animal style, then all the extras, but no sauce, but they never get that right; always ending up missing something. Extra stuff is always free, so it is like getting a burger and salad in one the way I order. 2 of them is plenty, and cheaper than any of the doubles they have on the menu.
Fries, if you get them, have to be well done to taste good.
There is an In-n-out across the street from RHV airport. I always try and time the visits for enough time to walk across the street.