The 13 best milkshakes in Chicago
Secret Shake at M Burger, $3.49
You already know that M Burger has a secret menu (right?). Along with extra hot hurt burgers and cheese fries, there's at least one secret shake at a time. No matter what this is, you want it—sometimes it's coffee, other times it's seasonal, like a mint-chocolate grasshopper for St. Patrick's Day, but it's always thick and delicious.