What Laws of Judaism Are Most Important to Keep As a Jew?

On my me-ander blog, I asked jbloggers to tell me what their "red line" is on Jewish observance.  I don't think I explained myself clearly.  I know that there's a very wide variety of "that's enough to be a good Jew" observances, individual "red lines." 

Recently a friend told me about a gifted young (eats kosher only) chef who's studying abroad and how he manages. 

But the real impetus to my question is something that happened decades ago.  I didn't know how to react then and the incident periodically pops into my mind.  I used to mock it, but now I realize that I should have shown more understanding.  The people involved have since passed away, and I'll try to blur the identities, not that I'm in touch with anyone who would know them.

Decades ago during one of my visits to my parents I saw some friends of theirs.  Nowadays many non-Orthodox Jews know of people who have become more religious than they had been raised to be, but in those days, I was an odd novelty. It was very common in my parents' generation to shed most religious observance.  My mother told me that it was expected, as the price of being good/real Americans.  They were horrified and shocked when I turned the tables and took on kashrut, Shabbat and more. 

These friends of my parents must have had been no older and probably younger than I am today, but they looked at me with my hair covered, long skirt and more children than they had, also their children's peer, as some sort of representative of G-d.  It was almost as if they were using the Catholic concept of a "confessional" hoping that I would tell them how righteous they still are.  I just remember myself standing in shocked silence, not knowing what to say.

Here's the story as I remember it:

We're still good Jews.  We try to be.  We fast on Yom Kippur, and believe me, it isn't always easy.  Last year we were visiting one of our children (note that I knew that the spouse wasn't Jewish, something they didn't mention but was ringing in my mind as I heard the story) and knew that Yom Kippur was that night.  We got to the restaurant* early enough so we'd finish eating on time, before the fast.  The service was awful.  Finally, I got up and yelled at them:

"Don't you understand?  Its almost time to start the Yom Kippur fast and we haven't been served our food yet!!!"

I just stood there and wonder to this very day how I should have reacted.  I used to think that religious observance had to be all or nothing, but as I've gotten older and seen more I realize that every mitzvah observed has its value.  By praising even partial, minimal observance there's more of a chance that observance will be continued and even increased.

Shavua Tov u'Mevorach

Have a Good and Blessed Week

*Yes, obviously it couldn't have been kosher.  I don't know if they made any efforts to eat kosher food or what their concept of kosher food was.