From the Arab Spring to a global economic crisis, from the destruction caused by an earthquake and tsunami in Japan to the killing of Osama bin Laden, 2011 has been defined by historic and dynamic events that will shape the world in the years ahead.

But which one was the top story of the year? We asked you, the readers, to vote and let us know what story was the most important for 2011.

We gave you 20 stories and asked you to list them in order of importance. More than 30,000 of you helped shape the list.

Here's what you decided were the top 10 stories of the year:

1. U.S. commandos kill Osama bin Laden in Pakistan raid

Navy SEAL Team Six became part of American military lore when the elite unit raided a compound in Pakistan in May, killing Osama bin Laden, the leader of al Qaeda and the most-wanted terrorist in the world, who orchestrated the terror attacks of September 11.

For Barack Obama, the bin Laden raid marked a high point of his presidency. Sometimes considered soft on terrorism, Obama achieved something his predecessor had failed to do: bring the mastermind to justice.

The killing came ahead of the 10-year anniversary of the September 11 attacks, which was marked by the opening of several memorials, including an outdoor tribute at ground zero in New York.

2. Japan suffers major earthquake, tsunami and resulting nuclear crisis

The earth shook off the coast of Japan in March, triggering one of the worst tsunamis in years, destroying nearly everything in its path and sending millions fleeing for high ground.

Beyond the utter calamity from the 9.0-magnitude earthquake, Japan found itself dealing with the worst nuclear crisis since the 1986 Chernobyl disaster. The Fukushima Daiichi nuclear facility was knocked offline, resulting in a meltdown of three reactors, with radiation leaking into the air and contaminated water spilling into the sea. The long-term effects from the stricken plant remain unknown.

3. Arab Spring spreads from Tunisia; regimes fall in Egypt, Libya

The revolt across the Middle East and North Africa began with the self-immolation of a struggling merchant in Tunisia and spread across the region. Egyptian protesters toppled the 30-year rule of Hosni Mubarak, and rebels in Libya battled supporters of long-time strongman Moammar Gadhafi.

Gadhafi was killed in October after months on the run from rebel forces and NATO bombardments.

4. Rep. Gabrielle Giffords is shot in the head at public event, survives

Rep. Gabrielle Giffords made what doctors call a miraculous recovery after she was shot in the head during a rampage at an Arizona supermarket in January. Six people were killed and 12 others wounded.

The man charged in the shooting, Jared Loughner, is in mental health treatment and will be re-evaluated early next year to determine his competency to stand trial.

5. Apple founder Steve Jobs dies of cancer at 56

Apple founder Steve Jobs, the genius who led the home computer revolution and inspired some the world's most popular mobile devices, died of pancreatic cancer in October.

"Apple has lost a visionary and creative genius, and the world has lost an amazing human being," Apple said in a statement on its website.

"Those of us who have been fortunate enough to know and work with Steve have lost a dear friend and an inspiring mentor."

Jobs final words, according to his sister, were "Oh, wow. Oh, wow. Oh, wow!"

6. Occupy Wall Street movement spreads from New York

What started as the Occupy Wall Street movement in New York in September has spread across major cities worldwide as a call to action against unequal distribution of wealth.

The movement gained massive global traction since protests began in New York. Protesters took to the streets in hopes of highlighting their unhappiness with current government and business tactics, which they say disproportionately helped what they dubbed the 1%, as opposed to everyday people, known as the 99%. They became viewed as a force that many cities had to figure out how to deal with. The movement gave many people who were unhappy with their current economic status the opportunity to be heard. It also gave way to many arrests. But most people are asking: Where does the movement head now, and will it become a force in the upcoming election?

7. Deadly tornadoes usher in year of severe weather

The largest tornado outbreak on record swept across across the South, Midwest and Northeast, with a record 207 touching down on April 27 and killing 346 people. Alabama bore the brunt of the destruction; a massive twister turned the college town of Tuscaloosa into a disaster zone.

Three weeks later, a mile-wide tornado ripped through Joplin, Missouri, killing more than 150 people and wreaking havoc across the blue-collar town at the edge of the Ozark mountains. It marked the deadliest single tornado in 60 years.

From Washington to New York in August, people braced for Hurricane Irene, a powerful storm that forecasters feared would cause catastrophic damage. The storm weakened before landfall, but it still was blamed for at least 20 deaths in eight states.

8. U.S. unemployment remains at staggering 9%

Jobs were at the center of economic and political debates in 2011, with unemployment rates hovering about 9%.

Politicians debated measures to get the economy going and businesses hiring.

They argued as they tried to figure out how to extend unemployment benefits for 6 million Americans who were at risk of losing them. And they argued over President Obama's jobs bill.

For many Americans, the economic struggles from the recessions were still lingering, and all they wanted was to be able to find work so they could support their families and pay their bills.

9. S&P lowers U.S. rating after 11th-hour deal to raise debt ceiling

Grueling negotiations over the debt-ceiling agreement, including threats of a possible government default if the deal collapsed, prompted Standard and Poor's to downgrade the United States from AAA to AA+, causing Wall Street to react with a drop of more than 600 points, one of its worst days in history.

The S&P downgrade prompted accusations of blame between Democrats and Republicans, exacerbating the already bitter partisan divide over the deficit talks.

10. Prince William marries Kate Middleton at Westminster Abbey

The world got a brief respite from doom-and-gloom headlines in April when Britain's Prince William and Catherine Middleton wed at Westminster Abbey.

Their wedding was one of the most-watched events of the year, from TV to the Internet. On the streets of London, many captured royal images on their mobile devices and instantly shared them with friends.