Growing up in the midwest, I've eaten at Steak 'n Shake more times than I can remember. My two favorite items are their triple Steakburger, and their Chili 5-Way. Up until recently, there was no Steak 'n Shake in my area, and while I couldn't duplicate their burgers (to be honest, I never really tried), I found that duplicating their chili wasn't all that hard.
Several of the popular brands of chili with beans prove to be a fair match, but what always set their chili apart was the special sauce. As it turns out, this is fairly easy to duplicate. Just whip up a batch, ladle chili over some spaghetti noodles, and drizzle this sauce over the top:
4 Tbsp catsup
1 Tbsp worcestershire sauce
4-5 dashes Tabasco pepper sauce
The above is good enough for a single serving, scale accordingly and to taste for the number of bowls you're serving.