I LOVE Yiddish! I don't speak it fluently (due to my hearing impairment, I have trouble understanding spoken words), but I can read it rather well. I taught myself how to read it with some help from an elderly neighbor in my childhood community. I also have many books about Yiddish and in Yiddish, and am trying to teach some to my children.
I was raised around Yiddish speakers only; as for Hebrew, I only know synagogue Hebrew, not secular Hebrew (which IMO is a good thing!)
To this day the expressions I am most comfortable with which refer to Hashem are the Yiddish terms (such as der Aybishter.)