Haribo Gummibärchen (gummy bears). The ones produced for the german market are much better than the ones for the US market.

If you like it: Müsli, much better than Cornflakes.

This is funny. Last time we were on an Austrian train, the attendant brought Haribo bears. My spousal unit tried to hide his excitement and finally asked, "Are you going to eat those?" "Gummy bears? Ummm . . . No." So he asked if he could, and was so happy. To eat a small bag of gummy bears. I could not for the life of me figure out what made these things so special. Gummy bears. Haribo gummy bears. German Haribo gummy bears.

Vitam-R. Like Marmite just much better.

Knorr and Maggi seasoning packs. They're easy to transport and an easy way to make German staple dinners like Gulasch or Geschnetzeltes and even the Currywurst mix isn't bad. Bautzner medium mustard, for me easily better than any mustard you can purchase in UK/Ireland or the U.S.

Not the OP, but I appreciate this tip! I like a good German mustard, but weirdly, it never occurred to me to buy one there--despite picking up mustard in France, even.