Duke, from your list I would say:
1) Bertie for throwing fuel on the fire and making the bubble worse
2) Cowen for trying to prevent a quick and corrective recession
I have to add the ECB up with Bertie for creating all the extra money and low interest rates. My reason is that the bubble is the disease and the recession is the cure. The ECB and Bertie created the bubble and therefore are most to blame.
Lets not forget the Parents.
The amount of people I know in N/E now who's parents basically nagged their kids to get on the ladder and all that is shocking. My parents did my head in with their constant 'advise'. Luckly I was well aware that my parents were morons and ignored them. Many didn't.