5. Tie – Angela Merkel and Nicolas Sarkozy

Europe is in dire financial trouble. With countries like Greece, Italy, Portugal and Spain deep in debt with seemingly no way out, Europe will be reliant on its strongest economies for bailouts. Germany and France, headed by Chancellor Angela Merkel and Nicolas Sarkozy respectively, are Europe’s best hope for saving its common currency, the euro. Introduced in 1999, its value is dependent on the economies of all of the countries that accept it as currency. With most of Europe in debt, however, there is fear of a potential collapse in the value of the euro. Going into 2012, Merkel and Sarkozy will be confronting Europe’s economic challenges. Only time can tell if they will succeed.

4. Catherine Middleton (Duchess of Cambridge)

In a year that seemed full of bad news, from an economic crisis to a devastating tsunami to repressive regimes in the Middle East, the world was able to take a break from distress in the form of an extravagant royal wedding. Middleton, now the Duchess of Cambridge, married Prince William on April 29 in a ceremony that was broadcast ubiquitously around the world. An estimated 122 million people around the world tuned in to watch the marriage and parade that followed, while thousands of people in London turned out along the parade route. After her engagement to Prince William, Middleton became an instant celebrity, and remains a prominent figure in the British royal family.

3. Naoto Kan

Being a head of state isn’t easy. Being a head of state during a once-in-a-century earthquake, tsunami and subsequent nuclear disaster is close to impossible. Nevertheless, Kan was at the forefront of efforts to rebuild Japan until he resigned on Aug. 10. The earthquake that struck Japan in March, a magnitude 9.0, triggered a massive tsunami that, combined, killed nearly 16,000 people. The earthquake also led to a meltdown at the Fukushima Daiichi nuclear power plant. Kan pledged to end Japanese overreliance on nuclear energy and explore all possible alternatives, putting legislation into place that would allow for such action before he resigned.

2. Adm. William McRaven

As the commander of U.S. Special Operations Command, nearly all of his work is top secret. He is, however, responsible for commanding the mission that killed Osama bin Laden in Pakistan this year. The operation, dubbed Neptune’s Spear, involved a Navy SEAL Special Forces team being airlifted into the compound where bin Laden was hiding. The team killed five people, including bin Laden himself, with the loss of one helicopter. Operation Neptune’s Spear may be his most high profile mission, but few others are ever made public. Navy SEALs and other Special Forces teams are responsible for carrying out high-risk missions that are often politically dangerous for the regular army to carry out.

1.  Mohamed Bouazizi

Whether or not you know his name, his influence throughout 2011 is all too apparent – and unbelievable, given his background. Bouazizi, a Tunisian fruit vendor, set himself on fire after a government official confiscated his weighing scales, which he needed to stay in business. His suicide sparked protests in Tunisia that forced the president’s resignation at the end of January, and led to protests in Egypt, Libya, Yemen, Syria, and other nations across the Arab World. “The protester” was named Time magazine’s Person of the Year, but one in particular – Bouazizi – is responsible for the unrest that rocked the world.