I think I saw an Adventskalender (marked as such) at the Giant Eagle Market District in Aspinwall the other day, with their holiday stuff. I can usually also find a few things like Vanillezucker and German Pickles for my Rouladen in their international section, as well as Knäckebrot in either the bread or crackers section and some Kinder products in the chocolate section. From time to time, their beer section also has Weihenstefaner Helles, which is the only real Helles I've been able to find in the city.

A couple others--Target sometimes has Ritter Sport and you can occasionally find Essig Essenz (important, IMO, if you're making Kartoffelsalat) at pan-Asian or Korean grocery stores because some people use it for kimchi.