A recent scientific article covered by the NYT shows how having access to affordable health insurance, in this case Medicaid, improves people's lives. It a "duh" article, but it's the first of its kind, because they were able to match SES and region and have a true control group. They found that when people have health insurance not only get more emergent care, but they get more preventative care, and have lower stress levels as well.
If you've never experienced the kind of challenges that being on the lower end of the income spectrum brings (or haven't been there for a while) you might want to check out this game http://playspent.org/ . It's amazing how well they made it fit so many life scenarios and how quickly it sets up the stress and anxiety that goes along with just making it.