If I told you I had a favorite scientist, I would be lying to you. Truth being that it's a tie between Nikola Tesla and Richard Feynman. And I was talking to my friend about Tesla after watching the latest Epic Rap Battle of History (see link) and he said "people don't know enough about Tesla" and I agree, so here we go.
The relationship between Nikola Tesla and Thomas Edison is pretty much flawlessly explained in an Oatmeal Comic ( http://theoatmeal.com/comics/tesla ) and I find the interesting part to me is that nobody knows about this guy. Everybody, and obviously I generalize, is taught the story of Edison. My father, for example, grew up in Detroit, and nearby there was the Henry Ford Museum, which had Edison's lab in it. And as a child he and his friends idolized Edison as the great American inventor. When I started to get into physics we learned of Tesla together and my father and I came to learn that Thomas Edison was kind of a jerk (see Oatmeal comic for details).
On a more scientific note; one of Tesla's greatest inventions (of many) was alternating current, which is a flow of electric current that periodically reverses direction and powers virtually everything electrical on the planet. It allows for longer transmissions of power at higher voltage and thinner wires as opposed to direct current. Notable examples of alternating current are radios (which Tesla also invented) AC circuits also employ capacitors and introductory and allow for a wider range of devices.
On a concluding thought, I'm quite a fan of upgrading technology because it's awesome, but it might interest you to know that the United States still uses essentially the same electrical grid as designed by Thomas Edison. While I'm sure he did a good job for his time, there is much talk of energy deficiency and it might be time for an upgrade.
http://www.youtube.com/watch?v=gJ1Mz7kGVf0
