Primary Communities of Belief

I continue to be confused in my life on what I think the best way is to practically organize primary communities of faith. There is the model, where a church offers its weekly service as well as other services (like youth, children, young adult, singles, adult classes, etc.). This model is easily the most frequently seen. Many of these churches now, however, also have a strong small group focus.

These small groups are advertised as primary communities within the larger church. These communities are effective. What I keep getting confused about, is which of these things is most important?

Am I worse of (actually, not by guilt, or by tradition) missing my small group meeting one week, or missing the Sunday large service? Would it be worse for a youth group member to miss youth services than to miss normal church service?

Again, I use worse, not demanding that every miss be a negative thing, but as a term of equating priority. Is there a sense that missing Sunday services (traditionally the most important) might not always be the most important? Is there a possibility that it is more healthy to miss church and go to small group, than to miss small group and make it to church?

I am looking for opinions on this.

Specifically, I'm looking for thoughts on worship, and tithing. Both of which are most often seen in the larger church setting, and rightly so, but are these the things that we place our primary importance on? Is worship and teaching more important than dialogue, discussion and prayer?

Feedback welcome, and expected :)