The UK's "weird" first-past-the-post system is very close to the US and French systems, and many others.
Unfortunately re-running data on past elections would be wildly misleading, as people vote with the knowledge of which parties stand a chance in their seat, and hence a lot of votes that might have gone for smaller parties in a more proportional system goes to one of the biggest parties.
But you might look to the EU Parliament elections for a demonstration of how different people here might vote (with the caveat that the issues are different, and so people might certainly vote differently) with a proportional system:
Unfortunately re-running data on past elections would be wildly misleading, as people vote with the knowledge of which parties stand a chance in their seat, and hence a lot of votes that might have gone for smaller parties in a more proportional system goes to one of the biggest parties.
But you might look to the EU Parliament elections for a demonstration of how different people here might vote (with the caveat that the issues are different, and so people might certainly vote differently) with a proportional system:
http://en.wikipedia.org/wiki/European_Parliament_election,_2...