Depending how far you want to avoid German products, here is some starting points:
Made in Germany: Most pencils (i.e. what you use in school)
Invented in Germany: Aspirin (as zd mentioned), frankfurters (hot dog), MP3, the pregnancy test, standard sizes for envelops, office paper, printers, notebooks, ring binder, filling cabinets
German brands: Hugo Boss, Escada, Siemens, Fanta soda (before Coke bought it – fantastisch, i.e. fantastic), Nivea, Agfa, Adidas, Puma