That's a very compelling question, particularly limited to the Philly market. I might say up front that I'm a tad surprised by the lack of replies supporting Wibbage, at one time or another, but that's just an opinion. Pressed, I'd probably pick something from that station's glorious run, but I also was strongly attached to another station that I'll mention to add some variety to the discussion.
Somewhere around 1970, plus or minus a year or two, after the Drake format had spread its wings, WHAT ran the format with for lack of a better term, black music.
Soul music, if you will, was what really grabbed me, and I liked the Drake format. Combining the two really grabbed me. The Johnny Mann singers weren't used (pretty sure), but the jingles were identical. Maybe it was the jingles I liked more than the format, but hearing that music, with those jingles really grabbed me. I only remember one of the jocks, Dan Henderson, who's voice was very appealing. It was good stuff.
If there were 1 show I'd like back, maybe even above Hy Lit's Hall of Fame Sunday shows, it would be John Records Landecker's Wednesday Night at the Memories which aired somewhere around 1968ish. I used to tape that show on reel to reel, and losing those tapes somewhere along the line was as disappointing as losing many of my old baseball cards.
Given the option of including other markets, without hesitation, the one station I'd bring back in a heartbeat would be WBLS around 1981. Frankie Crocker, Ricky Ricardo, Fast Eddie commercials, Friday, Saturday and lunch hour mix shows with Jonathan Ferring, Shep Pettibone and the like, all anchored by great music. Those tapes, I haven't lost, thankfully.