Okay, here goes.
Chili dogs and malts at Crown Candy Kitchen. The neighborhood isn’t very nice but the place is a St. Louis gem: http://www.crowncandykitchen.com/
Handmade custard at Ted Drewes is #2. There may be a linhe but it goes very quickly: They have two locations and the Chippewa one is already open for the season. Here’s their site: http://www.teddrewes.com/Drewes.asp
Burgers at O’Connell’s pub:
Here’s another board for you to browse as well:)http://www.chowhound.com/boards/8