Last year, the Norwegian Nobel Committee sparked a minor diplomatic row when it awarded the prize to Chinese dissident Liu Xiaobo; in 2009 it was no less provocative when it selected Barack Obama before the US president had even completed a year in office.

In 2011, arguably the most eventful year of the century so far, the committee has no shortage of candidates. But will it opt for safe, deserving cases such as a protagonist from the Arab spring, one of the perennial nominees like Helmut Kohl, or something more mischievous like the leading actors in the WikiLeaks revelations.

Read through the main contenders below and then vote for who you think should win - or use the comment thread below to tell us who else you think should be on the list.

Lina Ben Mhenni

Lina Ben Mhenni was teaching English at the University of Tunis, blogging and living with her parents when the revolutionary momentum began steadily building up in the months before Zine El Abidine was ousted in January this year.

Her blog, A Tunisian Girl, played a crucial role in the Tunisian revolution.

Ben Mhenni had been chronicling her daily life and thoughts online since 2007, dodging the ubiquitous censors. But as the revolutionary mood grew, her tone hardened.

Under her own name, she stubbornly published witness accounts of brutality, despite being followed by the secret police, having her home repeatedly ransacked, hard-drives stolen, and state authorities hacking her emails and Facebook accounts, and deleting material. The fact that she had undergone a kidney transplant and fought serious illness did not limit her.

She played a key role in the bloggers' anti-censorship demonstrations of May 2010, rallies that sparked a government crackdown and led to two other bloggers being arrested and briefly jailed.

Then in the winter of 2010, when the self-immolation of a vegetable-seller in Sidi Bouzid sparked street protests and brought live-ammunition from police snipers, she went to Tunisia's rural interior and posted videos and images of the dead and wounded. She also visited hospitals and wrote accounts of what she saw.

That type of material was not being published by the heavily controlled state media, and it helped galvanise people in Tunis and other cities, who then took to the streets.

Ben Mhenni, who has published a short book, A Tunisian Girl, about her involvement in the revolution describes herself as a "free electron". She is not a member of any party and resigned from the interim government's panel established to reform media, information and communication law, calling the set-up just window-dressing and that she was not being listened to.

Ben Mhenni learned of her Nobel peace prize nomination on Twitter and was shocked, but said that if she won she would dedicate the prize to "the martyrs and the wounded throughout Tunisia".

Memorial

Memorial has seen its members beaten and killed, but soldiers on in its uphill battle to defend human rights in Vladimir Putin's Russia.

The group was founded in the dying days of the Soviet Union, devoted to the gruelling task of recording the political repressions, arrests and murders carried out under the communist regime. To this day, its library welcomes Russians hoping to discover the truth about relatives who have long disappeared.

With branches across Russia and also in Ukraine, Memorial's Human Rights Centre focuses on fighting the human rights violations that have returned to the Russian landscape.

Russia's main problem, says Memorial's chairman, Oleg Orlov, is "the desire to not remember the tragic path the Soviet Union went down".

"We always said 'never again' – and we meant this in terms of political repressions. But now again we see political prisoners in Russia. We're slowly returning to our Soviet past."

Memorial helps organise legal aid for victims of human rights violations and works to publicise cases that find no place in Russia's largely state-controlled media.

It has been nominated for the Nobel peace prize alongside co-founder Svetlana Gannushkina, a 69-year-old firebrand who leads Russian attempts to battle the growing xenophobia afflicting the country. In addition to sitting on Memorial's board, Gannushkina heads the Committee for Civil Assistance, an NGO devoted to migrants' rights.

"The situation is getting worse," Gannushkina said. "It's thrown me into horror. Nationalism has been put forward as 'an opiate for the people' and it will lead to the break-up of Russia."

On a recent afternoon, Gannushkina's office was packed with migrants – men and women from ex-Soviet countries seeking to find a better life, and work, in Russia. Instead they are often met with police brutality, social violence and exclusion.

"I've always been that way – I can't stay out of other people's business," Gannushkina said, explaining why a trained mathematician would become one of Russia's leading human rights activists. "It's our duty to challenge this system," Gannushkina said, referring to Russia under Putin. "They want democracy only for themselves – but it doesn't work that way."

Julian Assange

Julian Assange, the editor-in-chief of WikiLeaks, is an outside bet for this year's Nobel peace prize, though, to some, he is a figure of some controversy.

Assange's whistleblowing website was behind the release of three of the biggest leaks in history: secret communiqués from US diplomats, military logs from Iraq, and war files from Afghanistan.

His supporters say he is a fearless champion of human rights and free speech; his detractors reckon him self-important, a man whose reckless disclosures endangered lives.

Assange has scooped several big prizes already. These include the 2011 Martha Gellhorn Prize for Journalism, as well as an award from Amnesty International. He is already on the Nobel prize shortlist after Snorre Valen, a young Norwegian politician, nominated him in February.

WikiLeaks is also credited with playing a role in the Arab spring – the site's leaked US diplomatic cables painting a vivid portrait of corruption and decadence among the now-deposed plutocrats of Tunisia, Egypt and Libya.

But the White House is likely to protest vigorously if Assange gets the prize. The US administration accuses the 40-year-old of spoiling relations with international partners, and it has been seeking a way, unsuccessfully so far, to prosecute him for treason.

It might also be tricky for Assange to collect the prize in person. He is living under curfew in Norfolk, appealing against extradition to Sweden, where he faces sexual assault allegations. Depending on how the legal process goes over the next couple of months he could either be in England or, if extradited and convicted, inside a Swedish prison cell.

Assange does have a broad and unusual coalition of backers. They include anti-war activists, information libertarians, and the Kremlin. In December, a member of Dmitry Medvedev's entourage proposed that the Australian activist and publisher be given the Nobel gong, a suggestion made seemingly to annoy Washington. Assange's recently published and disavowed autobiography makes a reference to the Nobel peace prize on the author's blurb. He might just pull it off.

Helmut Kohl

A Nobel peace prize nomination list would not be complete without the hulking form of the former German chancellor Helmut Kohl. The Nobel committee keeps nominations a secret for 50 years, but according to Der Spiegel, the 81-year-old colossus has received a nod every single year since 1990. That, of course, was when he achieved his greatest feat, of fusing two Germanys back into one – and defying Margaret Thatcher in the process.

The Iron Lady was fiercely opposed to reunification and made no secret of the fact. In his memoirs, Kohl recalled how Thatcher once grumbled: "We beat the Germans twice, and now they're back." Tough cheese, thought the truculent Kohl, and pushed hard for his motherland to be brought back together. On 3 October 1990, his mission was accomplished.

It was not an easy feat. Erich Honecker, who masterminded the construction of the Wall, and who later led the German Democtatic Republic, always claimed his creation would stand for 100 years – German citizens on both sides of the border believed him.

But even when the Wall fell in November 1989, reunification was not a foregone conclusion. The two Germanys used different currencies, one vastly richer than the other. Then there were the cultural and ideological differences forged through five decades of forced separation.

Twenty-one years on from the fall of the Wall, German reunification is largely considered a success. Germany is easily the richest and most powerful country in Europe and is a major player on the world stage. But will Kohl get the gong?

Surely the committee would have given him the prize in the 90s if they felt he deserved it? On the other hand, Kohl is a sick man. Confined to a wheelchair, he can no longer speak properly. With prizes only awarded to the living, this year could be his last chance.

Israa Abdel-Fattah

Israa Abdel-Fattah, also known as "Facebook Girl", worked in the HR department of a private Cairo firm when she helped to found the 6 April Youth Movement in 2008. The movement became a driving force during the street protests of the Egyptian revolution in 2011.

Abdel-Fattah was a young volunteer for el-Ghad party when she and two other young web activists decided to start a Facebook page inviting young people to join a strike movement organised for 6 April 2008 to support workers in El-Mahalla El-Kurba, an industrial town north of Cairo.

The Facebook group, backing the strike against inflation, corruption and police brutality, quickly gained tens of thousands of supporters and Abdel-Fattah came to the attention of the police. On the morning of the 6 April strike, she was arrested at a cafe near her office and held in prison for two weeks. Her arrest shocked the international community of cyber activists and became a rallying cause against censorship and repression.

On her release, Abdel-Fattah made a statement renouncing political activism and seemed to disappear from the protest scene. But in 2011, she returned to help co-ordinate the protests that toppled President Mubarak and was briefly detained again in January.

In Tahrir Square, she rallied young people pushing for democratic reform and became a regular spokesman in the international media for the protesters. During one protest in late January, she told the Guardian: "We don't want life to go back to normal until Mubarak leaves."

Wael Ghonim

Wael Ghonim was an Egyptian computer engineer and Google executive who managed Middle East marketing from Dubai, where he lived with his wife and children in a villa with a swimming pool, when he became the unlikely and reluctant hero of the Egyptian revolution.

Ghonim, who had a background in cyber activism, founded a Facebook page in July 2010 titled "We Are All Khaled Said", after a 28-year-old businessman was beaten to death by police in Alexandria, sparking protests. The page, run in his spare time, gained hundreds of thousands of followers and become a rallying point for young protesters to coordinate and organise the street demonstrations which eventually toppled Hosni Mubarak.

In January 2011, when the people's uprising was gathering force, Ghonim tricked Google into allowing him to return to Egypt, citing personal reasons. He was arrested and disappeared for 12 days while he was held in jail. He said he was interrogated over the "foreigners" said to be behind the protests, he was blindfolded and threatened with torture but not hurt.

On his release, he gave an emotional TV interview and when shown pictures of some of the 300 people who had died while he was in prison, he wept and walked off the set overwhelmed. He became a household name.

"I'm not a hero, I slept for 12 days," he said. "The heroes, they're the ones who were in the street, who took part in the demonstrations, sacrificed their lives, were beaten, arrested and exposed to danger."

He argued: "I only used the keyboard, the real heroes are the ones on the ground. Those I can't name."

He later addressed cheering crowds of protesters in Tahrir Square where he demanded the departure of the regime.

After the TV interview, over 130,000 people joined a Facebook page titled "I delegate Wael Ghonim to speak in the name of Egypt's revolutionaries".

Sima Samar

Sima Samar, the head of the Afghanistan Independent Human Rights Commission (AIHRC), embodies the struggle for women's rights in Afghanistan at a time when the limited gains made since the fall of the Taliban in 2001 are in doubt.

She was the first Hazara woman to qualify as a doctor in Afghan history but fled the communist regime in 1984 with her son after her husband was arrested. Across the border in Pakistan, she set up a medical centre for other Afghan women refugees in 1989, which she ran during more than a decade in exile.

After the fall of the Taliban, she returned to Afghanistan and became minister for women's affairs in Hamid Karzai's government. She received death threats for questioning restrictive laws affecting women, opposing the use of the burqa and the practice of purdah, and promoting education for girls. She has focused on health, particularly on the impact on the bones of a poor diet and a lack of sunlight for women in conservative families.

As a result of her outspoken comments, one conservative group denounced her as the "Salman Rushdie of Afghanistan" and she was ultimately forced to resign.

As well as running the human rights commission, Samar serves as a UN special rapporteur on human rights in Sudan.

Private Bradley Manning

The US soldier, Private Bradley Manning, is accused of leaking more than 250,000 secret diplomatic cables to Julian Assange – as well as the haunting video of a US Apache helicopter executing civilians in Baghdad.

Of all the protagonists in the WikiLeaks melodrama, it is Manning who has paid the highest personal price. He has spent the past year and four months in custody, most of it in solitary confinement.

US military investigators swooped in May 2010 after Manning allegedly confessed to downloading classified data from a facility in Iraq. But in the eyes of many he is a hero. His motives for allegedly leaking were clearly selfless and idealistic.

"It's important that it gets out ... I feel, for some bizarre reason...it might actually change something," Manning apparently confessed to fellow hacker Adrian Lamo.

In detention, US authorities sought to humiliate Manning, stripping him of his clothes, and prompting Amnesty International to raise its concerns.

Hardly surprising then that the Welsh-born Manning has been nominated for this year's Nobel peace prize. Like Assange, though, he would have a few problems travelling to Oslo to collect it. He is currently detained, awaiting court martial, in a medium-security prison in Fort Leavenworth, Kansas.

The White House would undoubtedly react furiously were the Nobel committee to give Manning, now 23, the prize – a bold gesture to whistleblowers every­where. The award would also make it harder for a US military court to hand Manning a punitive jail term. He would begin to look like a political prisoner.

Aung San Suu Kyi

Aung San Suu Kyi has already won the Nobel peace prize, 20 years ago. Then, however, the Burmese political activist was under house arrest in Rangoon and unable to attend the award ceremony in Oslo. Now, with rapid political changes in Burma, is it possible that one of the most famous pro-democracy campaigners might pick up a second award, this time in person?

No individual has ever won the award twice, but two organisations - the red cross and the UNHCR - have been awarded the peace prize more than once.

Aung San Suu Kyi is the daughter of General Aung San, one of the principal leaders of Burma's struggle for independence who was assassinated by political rivals in 1947 when she was a toddler. Educated in Delhi and Oxford, she has been a political activist since returning to her native land to look after her sick mother in 1988, a year of massive political upheavals.

Aung San Suu Kyi, charismatic, determined and striking, led mass demonstrations calling for democracy. She could not, she said, stand aside and watch. But the military junta brutally repressed all opposition. Despite the crackdown and their leader's house arrest, Aung San Suu Kyi's party, the National League for Democracy, won elections in 1990. The poll was, however, cancelled by the military rulers.

The Nobel prize rewarded "her unflagging efforts" and aimed to show "support for the many people throughout the world who are striving to attain democracy, human rights and ethnic conciliation by peaceful means".

Internationally famous, Aung San Suu Kyi was to remain confined to her home for 15 of the following 20 years. Last November, days after the party backed by the military authorities had won the first elections for two decades, Aung San Suu Kyi was released. Sidelined from the polls themselves, Aung San Suu Kyi has since maintained a sceptical stance, urging the international community to watch the small signs of reform in Burma closely for any sign of backsliding.