If you are facing the back, the "coveted seat" is the seat on any public bus all the way on the back, against the window on the left. Usually supplemented with a small bar behind the sideways seat in front of you for resting your right foot on. The window, even better when clean, also acts as an arm rest for you're right arm in most cases. You have a good view of the stops coming ahead and can enjoy the breeze best on a warm day, and are pretty close to the heat vents on a cold day.
two people sitting uncomfortably next to smelly bums. one guy pulls the dinger thing and gets out of the seat in the back left corner of the bus. Dude just got off, coveted seat is now available