If you are talking pure athlete, there is no contest in this one
Arnold `pop` Galiffa
He was the only 12 letter winner in army history, A finalist for the heisman, all american in baseball, and football, and there leading scorer in basketball
he was on the cover of life magazine
do a search and you will be amazed
he is from donora, pa a suburb he played sandlot ball with stan musial
Mario was not only the 2nd best player to play in the NHL, although it could be argued that Mario at his peak was better than Wayne. But he saved hockey in Pittsburgh twice. Once when he was drafted and Murtha threatened to sell the team and again when he bought the team. His contribution to the community with his golf outings and charitable contributions go a long way as well. Mario could run for Mayor and win.
Roberto would certainly have done the same if he were alive. A great player and great man as well.
Terry always held a grudge against the city because of the way he was treated in the early part of his career. He only came back last year to visit for the first time in 25 years.
All the others mentioned: Franco, Swann, Rocky et al are all great players but not in the top 5 in their sport or even position like Mario, Terry and probably Roberto. Given that Mario wins but Roberto would have made it a race if it wasn't for the crash.
Clemente in baseball.
Lemieux in hockey.
Greene in football.
Joe Greene is my pick because he was 1st and most important cornerstone on Steelers' great 70's championship teams.
A lot of people forget how dominating he was in his early seasons before he had much help.
how about athletes that are actually from the pittsburgh area(lived and went to high school). dan marino, joe montana, joe namath, tony dorsett, jim kelly, ty law-just to name a few