Beyond the whole issue of AC vs DC, Tesla created fluorescent light bulbs and showed that electricity could create radio waves, as well as activate objects wirelessly. Sadly, Edison was an idiot who had his mind on money and nothing else. Thomas Edison stopped at nothing to make Nikola Tesla look like a fool, just so edison could wire the US under his DC electricity. As a result, Tesla died in debt and never recognized his own briliance. Even at his death, the government demanded the opening of all his personal documents. It was like he wasan alien from another planet, and the military was stealing all of his tecnology. It should be noted that Tesla was a naturalized citizen of the US, never complained about his situation as he was constantly screwed over, and he held several patents that made his family wealthy. But he never realized that wealth.

2. Napoleon Bonapart

Most people recognize Napoleon as a short dictator who was evil to the core and hated Bugs Bunny, and was hated by the world. However, every part you thought was true from that last sentence is untrue.

  
First, Napoleon was not hated by the world, but mostly by the monarchs he deposed. He did not hate Bugs Bunny... only his characature did. He was not short, as he was measured by French standards. At 5 foot 2 inches French, he was truely 5 foot 6 and half by today's standards. That may not be a giant, but it is not short. Napoleon was also not a dictator nor did he rule as the evil villain he was depicted.
Napoleon Bonaparte was born into the lower nobility in Corsica, Italy. As Corsica was taken over by France, Napoleon surely found himself torn in loyalty as a young man. However he joined the French army and quickly rose through the ranks. As the French Revolution tore the country apart, Napoleon was detained and treated as a criminal, but eventually found freedom. The nation's internal conflict continued but Napopleon found his way into the comand of France's military. After endless battles in which he lead on the front line, and met miraculous victories, he was entered as a candidate for the leadership of France. This nation needed stability and someone to lead it out of the pit of despair it was currently suffering. Napoleon took it even farther, as he guided the french together under one goal. Their nationalism led to the illimination of many European monarchies, as the collective armies of Napoleon marched across the continent.
However, Napoleon shook up the monarch powers way too much, and led them to release their propaganda machine. As a result, his loss at Waterloo and to Admiral Nelson became kindling for a fire against Napoleon. Today he hardly remembered as anything but evil and the antichrist outside of France, but many in France remember him as the man who every ruler of their nation should be. Many westerners mock France as a bunch of cowards, but all you need to say is that Napoleon was a great and underrated ruler, and the French Underground helped save the allies during the first days following D-Day in WWII. Then you can get some respect from the French.

 
Napoleone. Qu'est-ce que c'est? Fafafafa...

1. Christopher Columbus

Yeah, he has a day specifically worshiped by Italians in the United States. Howard Zinn (in his usual loser, political, and non-historical style) likes to make him look like the Devil encarnate.

He wasn't the super explorer most people know. However, nothing much can be said for or about Christopher Columbus. No one can really decide on his nation of origin, or his real name. He's like Shakespeare, except everyone knows all there is to know about Bill.
Now, if this were a history by Howard Zinn, I would say, "Columbus set sail for the New World looking to wipe out all the indeginous people so that he could rape the land and have sex with their children." However, only a retard believes that.
Basically, everyone agrees that Columbus was Italian. As well, no one but idiots thought the world was flat when he was alive. Columbus' argument was that he could find a quick western route to the Indies. He wandered Europe trying to get funding, but was turned down at every step. Then he went to Spain, where the royalty was rich and liked stupid ideas, as long as they got rich.
As a result, Columbus got huge financial backing. He sailed west and found the Carribian. He never claimed to find a "new world", because that was not on his mind. He had found India, China, and Eden in the reality he saw. Also he broght back gold which made him famous. But, as the realization that this new region was more harsh than he realized became clear, his backing vanished and Columbus lost his money.
In the end, Columbus died believing he had found the western path to India. He had mapped a great deal of the West Indies and done a great service to Spain. However, he died a poor man, as he invested his entire life into what was seen as a failure. Later, many Europeans would become wealthy from the discovery that Columbus made. That is why we should celebrate him. Not as a guy who made it big on his luck, but a person who tried his luck and failed, yet paved the future for us as Americans.