I love authentic diners. Those little hole in the wall places that have mastered being unassuming and delicious and just concentrate on making great food quickly and aren't another trendy burger franchise trying to emulate that experience.
Chicago Hamburger Co. has that down. Their sliders are a little bigger than I thought they'd be but they're awesome and filling. Their fries are delicious and their milkshakes are just creamy deliciousness. Its tiny but the interior is homey and if you're in the area hit it for a nice meal you'll remember and savor enough to want to write a Yelp review about it,.
They even have a Rahm Emanuel for Mayor poster.