Press freedom in Ireland is the best in the world with three other countries coming joint first in a ranking by an international media body.
Ireland, Finland, Iceland and The Netherlands are joint top out of 168 countries in the ranking by Reporters Without Borders, the organisation which monitors and defends press freedom.
"Northern European countries once again come top of the index, with no recorded censorship, threats, intimidation or physical reprisals in Finland, Ireland, Iceland and The Netherlands, which all share first place," the organisation said.
The five worse violators of free expression were North Korea (bottom at 168th place), Turkmenistan, Eritrea, Cuba, Burma and China. Some countries have deteriorated, including Denmark, the US, France and Japan.
The US has fallen nine places to 53rd since last year, but slipped from 17th place in 2002. The organisation said relations between the media and the Bush administration deteriorated after the president used the pretext of national security to regard as suspicious any journalist who questioned his "war on terror".
Denmark, which ranked 19th, dropped from joint first place. The organisation said this was because of the serious threats against the authors of Muhammad cartoons published in 2005. France has also fallen five places during the past year, making a loss of 24 places in five years. This, the organisation, said was due to searches of media offices and journalists' homes.
Japan fell 14 places to 51st. The organisation said rising nationalism and the system of exclusive press clubs threatened democratic gains in Japan.
The newspaper Nihon Keizai was firebombed and journalists physically attacked by far-right activists.
Lebanon fell from 56th to 107th place in five years, as its media continued to suffer from the region's political atmosphere.
Two countries moved into the index's top 20 for the first time. Bolivia (16th) was best-placed among less-developed countries, and Bosnia-Herzegovina (19th) continued its gradual rise up the index and is now placed above neighbours Greece (32nd) and Italy (40th)
Ghana (34th) rose 32 places to become fourth in Africa.
A coup in Mauritius in August 2005 ended the heavy censorship of local media and the country has risen to 77th after being 138th in 2004, one of the biggest improvements in the index.
Compared to 2005, the UK fell from 24th place to 27th, Australia from 31st to 35th, Israel from 47th to 50th, Russia from 138th to 147th.
Iraq rose from 157th to 154th. Iran remained near the bottom at 162nd and Saudi Arabia at 161st.