David Dranove, The Economic Evolution of American Health Care, which I reviewed in the Wall Street Journal on January 8, 2001. It's an important look at the managed care revolution. He finds that managed care was an untold, until he wrote his book, success story. I like it much better than his more-recent Code Red, which I reviewed here [.pdf].
John L. Goodman and Gerald L. Musgrave, Patient Power. Dated in some ways but still good in others. Get the full version, not the abridged.