Simon Bolivar
From the time the first Conquistador gave a smallpox-infected blanket to an Incan villager the South American people were in the business of getting fucked by the Spanish. The Spanish crown spent the better part of three centuries looting gold and silver from South American mines and giving the native population death, disease and Catholicism in return. However, in a society where the native peoples are constantly being screwed over by foreigners, sometimes it only takes one man to stand up and say, "fuck this shit" to make a difference. In South America that man was Simón Bolívar.
Bolívar was born in Caracas, Venezuela in 1783. The son of aristocratic Spanish parents who died while he was still very young, Bolívar took an interest in the classical liberal ideals of the Enlightenment and dedicated much of his time to studying the American and French Revolutions and being pissed off at the antiquated idea of royalty. Once Napoleon decided to (in Bolívar's eyes) betray the ideals of the French Revolution and coronate himself as Emperor of France, Bolívar decided that was the last straw and moved back to Venezuela in 1810 to start kicking some asses.
Venezuela was already pissed off at this point because Napoleon had installed his brother Joseph as the King of Spain and South America, and in general the Venezuelan people were getting a little sick of Europe's bullshit. So in 1811 Simón Bolívar and the province of Venezuela formally declared their independence from Spain.
Naturally this didn't sit too well with Spain. They were like, "who the fuck do these assholes think they are?" and sent a dickload of well-trained, well-equipped, battle-hardened soldiers out to teach the Venezuelan people a lesson once and for all. Well once the Spaniards arrived they realized that war in South America doesn't really work the same as war in Europe, and all of a sudden the Spanish troops found themselves embroiled in a bloody guerrilla war with a small but mobile force of Venezuelan patriots under Bolívar's command.
For the next nine years, Bolívar would battle the Spanish across the mountains, valleys and forests of the Venezuelan countryside. Outnumbered, tired, hungry and under-equipped, Bolívar's men relentlessly continued their bloody war against colonial domination despite the knowledge that they were almost always just one battle away from having their revolution utterly crushed. Bolívar's Republican forces were thrown out of Venezuela by the Spanish on several occasions, but like a true badass he was not going to let a little beat-down stop him from achieving his goal. Every time he suffered defeat, he would turn right back around and start marching against Spanish outposts. Along the way Bolívar pretty much recruited anybody who was strong enough to pick up a rock and throw it at a Spanish person into his army. He took peasant villagers, farmers, boys, Spanish deserters, British and Irish mercenaries, space aliens and woodchucks into his army, fighting with antiquated muskets, sticks, machetes, shovels, knives, knees to the sack and pretty much anything else they had available to fight for their independance. The relentless attack of the Republican army eventually proved to be too much for Spain and in 1819 Bolívar marched triumphantly into Caracas, effectively liberating Venezuela from Spanish rule.
However, his work was not done yet. After his victory in Venezuela, Bolívar immediately undertook the incredible feat of crossing the Andes Mountain range into New Grenada (present-day Columbia), where his armies surprised the shit out of the Spanish army and won a series of sweeping victories. Before long, yet another province had been freed from Spain.
After the victory in New Granada, Bolívar turned his attention to Peru - the last bastion of Spanish dominion in South America. After a bloody war in the Peruvian mountains, the Republican forces expelled the last of the Spaniards from South American soil.
After these wars were over, the South Americans made Bolívar the President of the liberated territories. He had a grand vision of forming a confederation of South American states similar to that of the U.S.A. However, this was a little too radical for his time and he did not gain much support for this endeavor. After an assassination attempt, Bolívar decided to step down as the President of South America. He died in 1830, but has long since been known as "the George Washington of South America" and celebrated as a hero throughout the countries he freed.
"El Libertador" was a well-educated, determined badass who almost single-handedly liberated six countries from colonial rule: present-day Venezuela, Columbia, Ecuador, Peru, Panama and Bolivia. I mean shit, that has to be some sort of world record for "number of countries liberated by a single individual". The guy pretty much went all over the Northern part of South America battling the Spanish wherever he could find them, kicking ass and taking names. A truly underrated badass.