I'd also like to nominate Tim Horton's for ugliest Canadian establishment.
Seriously, who would enjoy sitting at that table next to those cars?!?
Everything here from the fact you have to cross a line of cars belching exhaust in your face to get inside the building, to the perpetually overflowing garbage bins, to the hideous pleated stretchy pants uniforms just adds to it's je ne c'est quoi. Anecdotally there is one near my house that they actually had to re-design the drive thru route because it so regularly clogged traffic on the main access road. Now it occupies a bigger chunk of the parking lot in a Disneyland-ride-style lineup which snakes back and forth.