Steak and Sheak double steakburger with pickles, onion, and mustard. That's good enough for me.
Although Steak and Shake wins in the condiments and vegetable toppings, In and Out actually uses a better tasting beef.
We verified this with additional visits to different In and Outs in different towns (as we perigrinated between Sandygo and LA visiting art galleries).
Ruby's (another California chain) was discovered to have hamburgers comparable to In and Out, and a highly complex menu, but the prices are more in line with a traditional restaurant.
"Steak and Shake double steakburger with pickles, onion, and mustard."
With an order of fries and an Orange Freeze. "It's a meal."