I can’t believe I’m the 2nd person to mention Gettysburg.
Also Beaver, Alaquippa, Erie, Lancaster, York, Johnstown, Altoona, Breezewood (ugh), Beaver Falls, Harrisburg, Monaca, Allentown.
No, can’t say I did.
And BTW, I call myself a “Johnstowner.” 
…I got nothin’.
Scranton.
Campaigned there several times for various candidates (also Allentown and Philadelphia, but Scranton more often). Also, kind of a geographical marker for long trips from where I live…“we’ll stop for gas when we get to Scranton,” that kind of thing.
Harrisburg, then Lancaster, then Gettysburg.
It’s a nice place toy visit; as long as you don’t run out of gas in Blue ball, or end up getting no further than Bird in Hand.
ETA: Sorta ninja’d by cochrane
Berwick, Shickshinny, Plymouth, Larksville, Edwardsville, Kingston, Forty Fort, Exeter, Dallas ----- want me to go on? But the two really important ones are Danville and Elysburg.
California
Ohiopyle (home of Fallingwater)
Butler
(For the record, anything in Allegheny County is usually considered part of Pittsburgh, at least to residents of PA)
The first and only one I thought of was Altoona. I do not know why. I have never been there and do not know anyone from PA.
Harrisburg
Erie, because I was born there.
Centralia, because it’s freaking on fire.
Harrisburg, because it’s the capitol.
Intercourse, because I’ll never be mature enough to not find that funny.
Allentown, Lancaster, York, Scranton, Wilkes Barre, Olyphant (had a girl friend from there), Easton, Stroudsberg, Paoli, Malvern, Media (my parents married there), Darby, Jenkintown, Chester, and, oh yeah, Harrisburg. I could go on.
This is another big one. Growing up a Civil War buff where I did, I made the (easy 90 minute) pilgrimage here more times than I can count. Can’t believe I didn’t mention it upthread.
(As a side note, may I say how awesome it was to grow up in central Maryland for this kind of thing? It feels as though 80% of the Civil War took place within a two-hour drive of my parents’ house.)
Lancaster. My grandfather lives there and my dad grew up there.
Scranton due to The Office
I don’t know how anything can be smaller than Ligonier. (My aunt lives there). Then again, there’s always Crabtree, although that’s really kind of part of Greensburg, really just a few cornfields. (My mother’s from Greensburg and I have family living in Crabtree)
BTW, if you do find yourself near Crabtree, GO TO CARBONE’S RESTAURANT. It is the best fucking Italian food in the whole entire world.
Shippensburg
First to come to mind was King of Prussia, because I knew some people who lived there once.
I’m kinda surprised that Breezewood didn’t come up first. I spent three days there once, when my U-Haul truck popped its pumpkin on the way down the mountain.
That was unpleasant.
Titusville
Oil City
Franklin
Altoona.