From an AM standpoint, I would have to say that WTAE/WEAE has been through the years.
If it weren't for WTAE, Phil Musick would have been a disgraced sportswriter, Doug Hoerth would have been a host that passed through KDKA, and Lynn Cullen would not be so revered by the liberals in town throughout her career.
This is before my time, but I wonder how much influence Myron Cope had in changing Pittsburgh from a Pirates to a Steelers town. Obviously the team's success would have made the change happen eventually, but if my sense of history was correct he was getting people to put up banners at Three Rivers Stadium, waving The Terrible Towel, and really getting the community into the team the way Bob Prince did with his Green Weenie.
More contemporarily, perhaps we could say that without Mark Madden, Mario Lemieux still would have been interested in buying the team out of bankruptcy to recoup his earnings.
But like him or not, can you deny Madden's influence had some bearing in keeping the arena issue alive when it appeared to be dead?
Or at the very least, other talk show hosts trying to copy his style? I remember when Thor Tolo tried to be a bit more confrontational to his callers- let alone in the Steelers press conferences- almost in responce to the guy.
And would hockey talk be so important for Pittsburgh sports talk show hosts if it wasn't for him? Maybe Stan and Guy's hockey show on Saturday mornings on WDVE and Sportbeat helped establish it first, let alone Tom McMillian during his time on WTAE in the '90s, but certainly Madden was the final link in making it so mainstream.
Later, when Paul Alexander hosted his sports talk show on KDKA, his promos had an announcer say something along the lines of "Sexism? Cutting you off? Not our style!"
Today, I still get the sense that "Stan and Guy" is THE sports talk show in town. No disrespect to any of the other sports stations, but all of the iconic sports talk shows in town have been on WTAE/WEAE at some point.