There are many reasons for converting to Judaism. Some are explainable and some are indescribable. I personally believe that it is a mixture of both. One reason for converting to Judaism is the realization that there is one true satisfying relationship, and it is with G-d. To achieve this goal one must be a true believer and follower of the Torah. Even though one can not follow it properly all the time, there is still a sense of spiritual belonging.
Judaism is not totally about the laws, it is about the unity of all Jews believing in G-d and G-d believing in the Jews. But mainly it is about the fashion of morality and dignity by which all Jews should conduct themselves by. Once one understands these and many other traits of the Torah, one can build a fundamental foundation of which one can live by.
