The thread title is made in such a vague way that this thread never looks likely to become much more than a collection of loosely grounded opinions.
When he lived in Ireland, my Dad told me that in a population of under four million, there were some eleven million private bank accounts. That must have made tax enforcement a challenge! It does not prove much though.
Perhaps we could have a thread in which we discuss, "Which country has the best bank robbers?", or "Which country has the meanest murderers?" Especially with a subject like corruption, on which the most knowledgeable people are the least likely to provide information, there is never likely to be a lot of solid facts to debate.
I would guess that Germany and the UK are at least as endemically corrupt as the Irish. I can't prove it though. How often is corruption actually proven anywhere?