Such exercises have always been the subject of criticism.

"How the hell can you tell?"

was John F Kennedy's not unreasonable response to a 1962 poll of 75 experts on the greatest US president. Leading British political commentator Peter Riddell described such assessments as "the ultimate parlour game for political junkies".

As a self-confessed 'political junkie', the temptation to undertake a similar exercise among Irish taoisigh has proven too great to resist. But, ranking the 11 men who have dominated the state's political scene, two caveats: one, the assessment is entirely personal and subjective;

and two, due to space considerations it isn't possible to rate them under a range of headings but merely to assess their impact both on the Ireland they led and the Ireland that came after them.

1= William T Cosgrave and Se�n Lemass (9/10) As president of the Executive Council, Cosgrave fulfilled the same role as taoisCMYK each, taking control of a new state overcoming a shattering War of Independence/Civil War. While his government arguably lacked imagination, its conservatism was just what was required. But nothing became Cosgrave more than how he handed over power to FF in 1932 - an event that caused much trepidation - crucially copper-fastening our democracy forever.

Most people's choice as our greatest ever taoiseach, Lemass oversaw a radical transformation in economic policy by moving away from the protectionist policies that had crippled the country. None of the other 11 taoisigh can match his record of delivery.

3= Albert Reynolds and Eamon de Valera (7/10) Reynolds achieves this high rating for one reason: the peace process. Politically, he was a poor taoiseach who oversaw the collapse of two governments in two years.

But, the most important single change that has occurred in Ireland over the past two decades is that people have stopped killing each other for political reasons and Reynolds' role in that must be acknowledged.

Eamon de Valera's record of 20 years in the top job will never be beaten and he remains the greatest statesman the country has ever produced. His dismantlement of the Treaty, drafting of the constitution and skillful handling of the Emergency will rank as his greatest achievements. However, he stayed in power too long and clung to an unrealistic image of Ireland as a rural idyll.

5. Bertie Ahern (6/10) His achievement in staying in government for a decade - and possibly longer - is phenomenal in politics today. In terms of political strategy, only de Valera is a match. But Ahern gets the high ranking because of his Northern achievements.

Where Reynolds brought can-do philosophy, Ahern brought negotiating nous.

He has presided over the country's greatest ever economic boom but is rightly criticised for failing to deliver more with the enormous resources at his disposal. He has also been reluctant to take on vested interests - particularly the trade unions.

6= Garret FitzGerald and Charles Haughey (5.5/10) FitzGerald's performance in delivering 70 seats for Fine Gael in 1982 is remarkable and his success in persuading Thatcher to agree to the Anglo-Irish Agreement was key to the subsequent peace process.

His constitutional crusade was visionary, although the country wasn't quite ready for it. He was unfortunate to lead the country during a brutal recession.

There is a compelling argument for Haughey to be bottom of the pile for the damage he has done to the reputation of politics in this country and for the shame he brought on the office of the taoiseach.

His first two terms in government were also disastrous. However, judged purely on results - on the impact on day-to-day lives - there is an argument for a higher rating based on his third term as taoiseach. His 1987-89 minority government took the unpalatable decisions that created the foundations for the Celtic Tiger.

8= Jack Lynch, John Bruton, Liam Cosgrave, John A Costello (5/10) It would be unfair to separate these four men without giving a much longer context.

Lynch was a genuinely decent man with a superb electoral record. He deserves credit for steering FF and the country through the Arms Crisis, a genuinely dangerous time for the state. But the 1977 election manifesto was the starting point for more than a decade of economic recession.

Bruton may have achieved a higher rating if he had stayed in the job longer. He was good on the economy but his record on the North was much less impressive.

Hugely honourable, Cosgrave's 1973-77 coalition was labelled the government of all-talents but it was beset by bad luck - a world energy crisis and a disastrous relationship with the O'Dalaigh presidency. Income tax rates that touched 77% didn't help its popularity, or the economy.

John A Costello served for two threeyear terms in the 1940s and '50s, tough economic times. His governments are best remembered for the controversy caused by the Mother & Child Scheme.