The Irish Times' resident Derry City supporting socialist Eamonn McCann today put forth a very intriguing argument in the pages in the paper of record today.
McCann's metric for determining the most successful team ever at a World Cup finals was fairly straightforward. He measured performance against population, dubbing that the only successful way to proceed. He reasoned that Northern Ireland's achievement in reaching the quarter finals in 1958 remains the greatest achievement in World Cup history.
He also threw in the fact that Norn Iron reached the last 12 in Spain '82 (different system then - 12 teams emerged from six groups and proceeded to play off in four groups of three. The team who topped these groups of three went onto the semi-finals).
Read the rest of his analysis here.