For the money, or any other reason, the Duquesne Incline provides one of the best Bangs For The Buck experiences in Pittsburgh.
Park free across the street at the base of the Incline. I like to take people up and back from the bottom at late dusk or darkness so they can enjoy the city lights at night.
YOU MUST HAVE EXACT CHANGE, NO EXCEPTIONS!
Lived here for years before I did it. Big omission.