The Olympics occupied just over a fortnight during a year which also saw volatile weather, the Diamond Jubilee and the first double-dip recession since the 1970s.
Asked to consider all these factors together, and to reflect on 2012 as a whole, 49% of respondents said the year made Britain a better place to live.
That compares with 41% who said the opposite, suggesting a positive public take on the Olympics was helping to colour wider perceptions of the year.
The overall verdict ought to surprise voters themselves, who in last year's Guardian Christmas poll told ICM by a 60%-30% margin that they expected Britain would become a more miserable place in 2012.
The vote of confidence in today's poll is even stronger than opinion taken at the height of the Games. In an online survey taken immediately after so-called 'Super Saturday' - on which Mo Farah, Jessica Ennis and Greg Rutherford all took track and field gold for Team GB:
- 55% agreed and 35% disagreed with the same proposition
- Pollsters, who interviewed 1,002 adults, said the Paralympics may have helped to cement this majority
- A crushing margin in favour of London 2012 was found in every social class and also in every region
Nearly 80% of Britons think the £9 billion spent on the Olympic Games was value for money.
A new poll by Guardian/ICM shows that 78% of voters believed the Olympics "did a valuable job in cheering up a country in hard times", compared with just 20% who looked back on them as "a costly and dangerous distraction".