1. Not everyone agrees with his motives, but by bringing Edward Snowden's accusations about US and UK surveillance to light, The Guardian started a global debate on what states know about our online activity.
2. After exposing how the sexual abuse of girls in the north of England was allowed to continue for years, The Times has set the agenda for child protection reform.
The Times' investigations editor Andrew Norfolk - winner of the Paul Foot Award for investigative journalism - uncovered the scandal of local authority-run care homes effectively ignoring and even condoning sexual abuse of girls as young as 13, with the criminal justice system unwilling to tackle the problem. Last year, nine men from Rochdale, aged between 22 and 59, were jailed for a string of offences related to sexual abuse.
Just last week, a review by the Rochdale Safeguarding Children Board laid bare the failings of local services and child protection agencies, who made "moral judgements" about the vulnerable girls, because of their class and background.
This was a great example of an awful story, which wouldn't have come to national attention were it not for one reporter asking difficult questions.
3. The Sunday Times's exposure of David Hunt as the leader of a sophisticated crime network.
In 2010, journalist Michael Gillard reported how Hunt was the head of a criminal network "so vast that Scotland Yard regards him as ‘too big’ to take on".
That resulted in a fiercely contested libel action in the High Court in which Hunt attempted to defend his reputation. But in July The Sunday Times won, with the judge calling the paper's work "serious investigative journalism" that had been carried out "fairly and responsibly". The evidence submitted proved, he ruled, that Hunt was "the head of an organised crime network, implicated in extreme violence and fraud."
He said: "This was a serious piece of investigative journalism which was expressed in forthright, but not extravagant terms; and without tangential additions to liven up the story."
Defending a libel suit by justification - by arguing that the original story was true - is made especially hard by the UK's stringent defamation laws, making this a significant victory for journalism and one of the most hard-fought newspaper stories in recent history.
4. The Mail on Sunday's expose of hapless Co-Operative Bank chairman Paul Flowers was a real scoop.
5. The Daily Mirror found a member of the House of Lords was turning up to Parliament for barely 30 minutes to claim his £300-a-day fee.
6. The Sunday Times won a long-running battle against disgraced cycling champion Lance Armstrong, who finally admitted - as the paper had long alleged - a history of using banned substances.
7. The Observer uncovered disturbing allegations of sexual abuse at the Yarl's Wood immigration detention centre.
8. The Manchester Evening News found a church selling olive oil and blackcurrant cordial as cures for cancer.
9. The Yorkshire Post wrote a string of stories about police payments and perks, involving abuses of power and conflicts of interest.
10. The Daily Telegraph and BBC Panorama caught Patrick Mercer MP offering to promote Fiji's campaign to re-join the Commonwealth in return for £2,000 a month.
11. Not an act of journalism, more an act of defiance. The Spectator said in very clear language that it would not be signing up for the government's press regulation scheme.
12. Rob Evans and Paul Lewis of The Guardian lifted the lid on the extent to which undercover police officers have infiltrated dissident groups by using false identities.
13. Exaro uncovered evidence of suspected child abuse stretching back 30 years.
The online investigative journalism startup in February revealed the existence of a police investigation into a suspected "VIP paedophile ring", with links to Jimmy Saville, and police plans to arrest a former Conservative cabinet member in relation to child abuse.
The dogged reporting from David Hencke and others, often in partnership with newspapers and broadcasters, has continued through the year and broken many stories.