Family Ties was the opitome of a situation comedy. If you hadn't been in that particular situation, then you wouldn't laugh. This is perhaps why it never received much love and still isn't getting it in syndication.
My favorite episode isn't even a funny episode. It wasn't really meant to be though. "My name is Alex" was shot much like a play and deals with the effect of a friend's death on Alex.
Some of the stronger episodes in the show were when the focus was on Alex and Ellen's relationship.
Ultimately, the show was just too PG for the masses. It didn't paint an accurate enough picture of the "me" generation.
The finale was half comedy, half introspective drama with Elyse coming to grips with the reality of Alex moving to New York.