I thought about this for awhile - and I have to say that antibiotics are one of those things that probably would have gotten my vote 10 years ago, but now with all sorts of resistant strains of bacteria, I'm really not sure about their value at times.

My vote was for vaccinations, but my real opinion at the moment is for ZiCam and Airborne - I am fighting off a cold and so far so good :).

Sanitation, without question. Modern plumbing has saved more lives than all the others put together.

One of my greatest regrets of life is that I found out about them after I was over 12 years old.

Urgent Care centers. Twenty bucks less than the ER and not nearly as diagnostic!

Well germ theory led to the development of the ideas of hygeine and antibiotics, so that's really the clear winner here. I'd like to give an honorable mention to vaccines -another extension- because in order for people to benefit from most medical technology, they need to get through childhood, and vaccinations against measles, smallpox, Tb etc have played a huge part in this, and continue to do so. Although measles is still one of the two biggest childhood killers in Africa .

Perhaps we should add charitable donations/financial support as an option?