Torah: Judaism is truly the only religion with a book of laws (and millions of them) that guide your way of life. The Jewish culture is all about the Torah. We believe that the world was created because of the Torah and everything revolves around the Torah.
Derech Eretz: Yaffa Torah Im Derech Eretz is a major factor. The Chachamim stress on Derech Eretz and make it a basis for our culture. While the secular world recently invented ethics, Jews had it since the giving of the Torah. Kibud Av V’Em is actually one type of Derech Eretz. Our entire focus is Derech Eretz (Chillul Hashem) and even the Torah had it in mind (D’racheha Darkei Noam). A Jew can be seen from the far because of Derech Eretz.
Gemilas Chasadim: One of the three pillars that supports the world and one of the three things the Gemara hails the Jewish nation. Gemilas Chasadim is in our fiber. Take a look at the thousands of Jewish organizations, look at how one Jew would do anything to help another. It’s an amazing part embedded in our culture.
I would say other things first such as Emunah & Bitachon, Areivim, Olam Habah, Schar V’Onesh, Mashiach, Eretz Yisroel, Simchas HaChaim, Mistapek B’Miut but I chose those that an outsider will recognize and be astounded. Every Goy can tell you they have faith etc. but they don’t know what faith is. It isn’t that easy to explain. Those three are explainable and obvious.