Of all the movies Kinski has done I saw Aguirre and "The Great Silence". I really liked Aguirre because it has a more positive vibe to it. The anti-happy-end of "The Great Silence" is also very appealing, yet really depressing.
Nevertheless, certainly one of the best movies I've ever seen. You can say what you want about Kinski, he was a great actor and I highly recommend watching at least some of his movies.