Pennsilfaanisch Deitsch.
Nevertheless, when my father was talking privately with me he would tell me Hochdeutsch jokes: eg., Was ist los?---Was ist nicht verbunden is los."---funny stuff, huh?
I can sort of understand Pennsylvania Deutsch -- but believe it or not it's easier for me to understand Yiddish!
I learned German from an Austrian, so I'm about as far from the Plattdeutsch/Low German dialects as anybody can be on the language map. She tried to teach us a little Plattdeutsch, and I've read some of it in Grimm's Tales, but it just doesn't compute for me.