The full list I can’t write, as I don’t know. Here that is at me.
In German:
KQ6
Gabriel Knight 1
SQ4
SQ5
Torin Passage(in German is text only)
Freddy Pharkas
Conquests of the Longbow
Also I have versions of various Sierra games in Spanish, Italian, French, Polish, Russian. But some of them is UNofficial translations.