I think the Mass. plan is the best solution I've heard. Uninsured people do, as you said, use emergency rooms too much. That's terribly expensive, and paid for by taxes.
Insured people are much more likely to visit doctors or clinics, a much cheaper way to provide health care.
Best of all, it keeps health care in the private sector. We can all buy the best insurance we want, or can afford.
I'd like to see several states try this before we even talk about gov't provided health care.
You don't mind having 4% of your earnings go for healthcare for illegal aliens? That is part of the California plan.