I grew up in southern IA with tenderloin sandwiches, and my parents can currently get them in southern MO. I'm now in FL and miss them. I did find a bar in Daytona run by Indy natives that had a pretty good one.
We also just got a Culvers. I maaaaaaay have to drive over there to check it out! I had no idea they had them.
Adding more to my list - Casey's pizza. It's gas station pizza at it's finest. Also, when my dad first moved to FL years ago, he missed Cookie's barbecue sauce, and Dorothy Lynch salad dressing. He would bring some home every time he went back.