A whopping 955,000 tuned in to see the conclusion of the series this year to witness Nidge finally topple kingpin John Boy.
RTE said that demand for series one was so big that the DVD series has been repressed.
It has also been sold to Scottish TV (STV) and is currently being screened by Foxtel in Australia.
And a total of 20pc voted that the gangland series was their favourite programme of the year while David Attenborough's acclaimed Frozen Planet was a close second place at 19pc.
American courtroom drama The Good Wife secured the third place.
Television and service provider UPC have carried out the research into the nation's TV habits in 2011.
And despite strong performances from Irish star Janet Devlin, the X Factor proved to be the biggest disappointment for viewers. More than one third said that the singing competition was the biggest let down of the year, followed closely by The Apprentice and US airline drama Pan Am.
Looking ahead to 2012, most viewers are gripped by the Fifties advertising world Mad Men and the romantic tension in Downton Abbey.
Families across Ireland placed Home Alone as the top Christmas movie to watch on December 25.
A quarter of the population admitted to vegging out in front of the TV for between three and five hours.
But head of television, Simon Kelehan, said that families are not always peaceful when it comes to choosing the programme to watch over the festive season as more than two thirds don't get to watch what they want.
"To avoid any arguments this year, we recommend that people set their DVRs so they can catch up with their programmes at a later date," he added.
More than a third of people are planning to tune in EastEnders and Coronation Street on Christmas Day.