Philadelphia has 5 main pockets of wealth within its metro:
1.
Center City, but specifically Rittenhouse Square and Society Hill but also Fitler Square, Wash Square, and Logan Square. Obviously, very urban.
The next two are inner-rung suburbs, mostly older with a mix of enormous estates and small towns.
2. The storied
Main Line suburbs starting at the NW city line and radiating west along Rt. 30 and the Paoli train line. Bala, Gladywn, Ardmore, Brywn Mawr, Haverford, Radnor, Villanova, Berwyn, Devon, Malvern. I'd also throw Newtown Square into that mix.
3.
Germantown/Stenton Corridor. What? Starting from Chestnut and W. Mount Airy (within city limits) and including parts of Flourtown, Fort Washington (
Sheaff Lane), Whitemarsh (Andorra Road,
Harts Lane), and Blue Bell (Ryan Howard lived here).
The last two are on the periphery of the metro area and have that wealthy rural feel to them - you know, rolling hills, winding country lanes, picket fences, gentleman's farms, etc.
4.
Chester County "Horse Country" centered around Kennett Square, Chadds Ford, Popsocon (remember Bam Magera's house?!), and Longwood.
5.
Bucks County along the Delaware, North of Newtown (wealthy in its own right but mostly overrun with McMansions), including Wrightstown, Buckingham, New Hope/Solebury, and Lahaska (Peddler's Village).
Also, I would not consider Greater Princeton to be a wealthy NYC suburb. It's really its own thing.