1. Antibiotics for serious diseases like pneumonia, syphilis, and staph infections that used to cost people limbs
2. The vaccines that wiped out smallpox and have almost wiped out polio (barring places like Afghanistan and Pakistan that are killing aid workers distributing vaccine, calling it unIslamic, not carrying if kids are left crippled instead)
3. Guinea worm disease, a horrific mutilating parasite, almost wiped out by a charity Jimmy Carter supports. Probably eradicated in the next five years.